# Ethernet

[中文]

## Overview

ESP-IDF provides a set of consistent and flexible APIs to support both internal Ethernet MAC (EMAC) controller and external SPI-Ethernet modules.

This programming guide is split into the following sections:

> 1. Basic Ethernet Concepts

> 2. Configure MAC and PHY

> 3. Connect Driver to TCP/IP Stack

> 4. Misc Control of Ethernet Driver

## Basic Ethernet Concepts

Ethernet is an asynchronous Carrier Sense Multiple Access with Collision Detect (CSMA/CD) protocol/interface. It is generally not well suited for low-power applications. However, with ubiquitous deployment, internet connectivity, high data rates, and limitless-range expandability, Ethernet can accommodate nearly all wired communications.

Normal IEEE 802.3 compliant Ethernet frames are between 64 and 1518 bytes in length. They are made up of five or six different fields: a destination MAC address (DA), a source MAC address (SA), a type/length field, a data payload, an optional padding field and a Cyclic Redundancy Check (CRC). Additionally, when transmitted on the Ethernet medium, a 7-byte preamble field and Start-of-Frame (SOF) delimiter byte are appended to the beginning of the Ethernet packet.

Thus the traffic on the twist-pair cabling appears as shown below:

Ethernet Data Frame Format

### Preamble and Start-of-Frame Delimiter

The preamble contains seven bytes of `55H`. It allows the receiver to lock onto the stream of data before the actual frame arrives.

The Start-of-Frame Delimiter (SFD) is a binary sequence `10101011` (as seen on the physical medium). It is sometimes considered to be part of the preamble.

When transmitting and receiving data, the preamble and SFD bytes will be automatically generated or stripped from the packets.

### Destination Address

The destination address field contains a 6-byte length MAC address of the device that the packet is directed to. If the Least Significant bit in the first byte of the MAC address is set, the address is a multicast destination. For example, 01-00-00-00-F0-00 and 33-45-67-89-AB-CD are multi-cast addresses, while 00-00-00-00-F0-00 and 32-45-67-89-AB-CD are not.

Packets with multi-cast destination addresses are designed to arrive and be important to a selected group of Ethernet nodes. If the destination address field is the reserved multicast address, i.e., FF-FF-FF-FF-FF-FF, the packet is a broadcast packet and it will be directed to everyone sharing the network. If the Least Significant bit in the first byte of the MAC address is clear, the address is a unicast address and will be designed for usage by only the addressed node.

Normally the EMAC controller incorporates receive filters which can be used to discard or accept packets with multi-cast, broadcast and/or unicast destination addresses. When transmitting packets, the host controller is responsible for writing the desired destination address into the transmit buffer.

### Source Address

The source address field contains a 6-byte length MAC address of the node which created the Ethernet packet. Users of Ethernet must generate a unique MAC address for each controller used. MAC addresses consist of two portions. The first three bytes are known as the Organizationally Unique Identifier (OUI). OUIs are distributed by the IEEE. The last three bytes are address bytes at the discretion of the company that purchased the OUI. For more information about MAC Address used in ESP-IDF, please see MAC Address Allocation.

When transmitting packets, the assigned source MAC address must be written into the transmit buffer by the host controller.

### Type/Length

The type/length field is a 2-byte field. If the value in this field is <= 1500 (decimal), it is considered a length field and it specifies the amount of non-padding data which follows in the data field. If the value is >= 1536, it represents the protocol the following packet data belongs to. The following are the most common type values:

> - IPv4 = 0800H

> - IPv6 = 86DDH

> - ARP = 0806H

Users implementing proprietary networks may choose to treat this field as a length field, while applications implementing protocols such as the Internet Protocol (IP) or Address Resolution Protocol (ARP), should program this field with the appropriate type defined by the protocol's specification when transmitting packets.

### Payload

The payload field is a variable length field, anywhere from 0 to 1500 bytes. Larger data packets violates Ethernet standards and will be dropped by most Ethernet nodes.

This field contains the client data, such as an IP datagram.

### Padding and FCS

The padding field is a variable length field added to meet the IEEE 802.3 specification requirements when small data payloads are used.

The DA, SA, type, payload, and padding of an Ethernet packet must be no smaller than 60 bytes in total. If the required 4-byte FCS field is added, packets must be no smaller than 64 bytes. If the payload field is less than 46-byte long, a padding field is required.

The FCS field is a 4-byte field that contains an industry-standard 32-bit CRC calculated with the data from the DA, SA, type, payload, and padding fields. Given the complexity of calculating a CRC, the hardware normally automatically generates a valid CRC and transmit it. Otherwise, the host controller must generate the CRC and place it in the transmit buffer.

Normally, the host controller does not need to concern itself with padding and the CRC which the hardware EMAC will also be able to automatically generate when transmitting and verify when receiving. However, the padding and CRC fields will be written into the receive buffer when packets arrive, so they may be evaluated by the host controller if needed.

Note

Besides the basic data frame described above, there are two other common frame types in 10/100 Mbps Ethernet: control frames and VLAN-tagged frames. They are not supported in ESP-IDF.

## Configure MAC and PHY

The Ethernet driver is composed of two parts: MAC and PHY.

The communication between MAC and PHY can have diverse choices: MII (Media Independent Interface), RMII (Reduced Media Independent Interface), etc.

Ethernet RMII Interface

One of the obvious differences between MII and RMII is signal consumption. MII usually costs up to 18 signals, while the RMII interface can reduce the consumption to 9.

Note

ESP-IDF only supports the RMII interface. Therefore, always set `eth_esp32_emac_config_t::interface` to `eth_data_interface_t::EMAC_DATA_INTERFACE_RMII`.

In RMII mode, both the receiver and transmitter signals are referenced to the `REF_CLK`. `REF_CLK` must be stable during any access to PHY and MAC. Generally, there are three ways to generate the `REF_CLK` depending on the PHY device in your design:

- Some PHY chips can derive the `REF_CLK` from its externally connected 25 MHz crystal oscillator (as seen the option a in the picture). In this case, you should configure `eth_mac_clock_config_t::clock_mode` of `eth_esp32_emac_config_t::clock_config` to `emac_rmii_clock_mode_t::EMAC_CLK_EXT_IN`.

- Some PHY chip uses an externally connected 50 MHz crystal oscillator or other clock sources, which can also be used as the `REF_CLK` for the MAC side (as seen the option b in the picture). In this case, you still need to configure `eth_mac_clock_config_t::clock_mode` of `eth_esp32_emac_config_t::clock_config` to `emac_rmii_clock_mode_t::EMAC_CLK_EXT_IN`.

- Some EMAC controllers can generate the `REF_CLK` using an internal high-precision PLL (as seen the option c in the picture). In this case, you should configure `eth_mac_clock_config_t::clock_mode` of `eth_esp32_emac_config_t::clock_config` to `emac_rmii_clock_mode_t::EMAC_CLK_OUT`.

Warning

If the RMII clock mode is configured to `emac_rmii_clock_mode_t::EMAC_CLK_OUT`, internal Audio PLL clock is used as a source of 50 MHz clock. Hence be sure it is not in collision with I2S bus configuration.

When internal clock is selected, then `GPIO0` can be used to output the `REF_CLK` signal. However, the clock is outputted directly to the GPIO in this particular case and so it does not have direct relationship with EMAC peripheral. Sometimes this configuration may not work well with your PHY chip. If you are not using PSRAM in your design, GPIO16 and GPIO17 are also available to output the reference clock signal. The source of clock is the same (APLL) but these signals are routed from EMAC peripheral.

If the RMII clock mode is configured to `emac_rmii_clock_mode_t::EMAC_CLK_EXT_IN`, then `GPIO0` is the only choice to input the `REF_CLK` signal. Please note that `GPIO0` is also an important strapping GPIO on ESP32. If GPIO0 samples a low level during power-up, ESP32 will go into download mode. The system will get halted until a manually reset. The workaround for this issue is disabling the `REF_CLK` in hardware by default so that the strapping pin is not interfered by other signals in the boot stage. Then, re-enable the `REF_CLK` in the Ethernet driver installation stage.

The ways to disable the `REF_CLK` signal can be:

- Disable or power down the crystal oscillator (as the case b in the picture).

- Force the PHY device to reset status (as the case a in the picture). This could fail for some PHY device (i.e., it still outputs signals to GPIO0 even in reset state).

Warning

If you want the Ethernet to work with Wi-Fi or Bluetooth, don’t select ESP32 as source of `REF_CLK` as it would result in `REF_CLK` instability. Either disable Wi-Fi or use a PHY or an external oscillator as the `REF_CLK` source.

No matter which RMII clock mode you select, you really need to take care of the signal integrity of REF_CLK in your hardware design! Keep the trace as short as possible. Keep it away from RF devices and inductor elements.

Note

Signals used in the data plane are fixed to specific GPIOs via IO_MUX, they can not be modified to other GPIOs. Signals used in the control plane can be routed to any free GPIOs via Matrix. Please refer to ESP32-Ethernet-Kit for hardware design example.

You need to set up the necessary parameters for MAC and PHY respectively based on your Ethernet board design, and then combine the two together to complete the driver installation.

Basic common configuration for MAC layer is described in `eth_mac_config_t`, including:

- `eth_mac_config_t::sw_reset_timeout_ms`: software reset timeout value, in milliseconds. Typically, MAC reset should be finished within 100 ms.

- `eth_mac_config_t::rx_task_stack_size` and `eth_mac_config_t::rx_task_prio`: the MAC driver creates a dedicated task to process incoming packets. These two parameters are used to set the stack size and priority of the task.

- `eth_mac_config_t::flags`: specifying extra features that the MAC driver should have, it could be useful in some special situations. The value of this field can be OR'd with macros prefixed with `ETH_MAC_FLAG_`. For example, if the MAC driver should work when the cache is disabled, then you should configure this field with `ETH_MAC_FLAG_WORK_WITH_CACHE_DISABLE`.

Specific configuration for internal MAC module is described in `eth_esp32_emac_config_t`, including:

- `eth_esp32_emac_config_t::smi_mdc_gpio_num` and `eth_esp32_emac_config_t::smi_mdio_gpio_num`: the GPIO number used to connect the SMI signals.

- `eth_esp32_emac_config_t::interface`: configuration of MAC Data interface to PHY (MII/RMII).

- `eth_esp32_emac_config_t::clock_config`: configuration of EMAC Interface clock (`REF_CLK` mode and GPIO number in case of RMII).

- `eth_esp32_emac_config_t::intr_priority`: sets the priority of the MAC interrupt. If it is set to `0` or a negative value, the driver will allocate an interrupt with a default priority. Otherwise, the driver will use the given priority. Note that Low and Medium interrupt priorities (1 to 3) can be set since these can be handled in C.

### Memory Considerations when Using Internal MAC

The internal MAC subsystem transfers data to and from the CPU domain via DMA using a linked list of descriptors. There are two types of descriptors: Transmit and Receive. Based on its type, a descriptor holds status information about the received or transmitted frame or provides controls for transmission. Each descriptor also contains pointers to the current data buffer and the next descriptor. As such, a single EMAC DMA descriptor has size of 32 bytes in DMA-capable memory.

The default configuration should cover most use cases. However, certain scenarios may require configuring the Ethernet DMA memory utilization to suit specific needs. Typical problems may arise in the following situations:

- Short and frequent frames dominate network traffic: If your network traffic primarily consists of very short and frequently transmitted/received frames, you may observe issues such as lower-than-expected throughput (despite the rated 100 Mbps) and missed frames during reception. On transmission, the socket send API may return `errno` equal to `ENOMEM`, accompanied by the insufficient TX buffer size message (if debug log level is enabled). This is because the default memory configuration is optimized for larger frames; CONFIG_ETH_DMA_BUFFER_SIZE is set to 512 bytes by default to ensure a better data buffer to descriptor size overhead ratio. The solution is to increase CONFIG_ETH_DMA_RX_BUFFER_NUM or CONFIG_ETH_DMA_TX_BUFFER_NUM. Additionally, consider decreasing CONFIG_ETH_DMA_BUFFER_SIZE to match the typical frame size in your network to maintain a reasonable memory footprint of the Ethernet driver.

- High throughput leads to buffer exhaustion: If the socket send API intermittently returns `errno` equal to `ENOMEM`, accompanied by the insufficient TX buffer size message (if debug log level is enabled), and the throughput is close to the rated 100 Mbps, this likely indicates nearing hardware limitations. In such case, the hardware cannot keep up with the transmission requests. The solution is to increase CONFIG_ETH_DMA_TX_BUFFER_NUM to buffer more frames and mitigate temporary peaks in transmission requests. However, this will not help if the requested traffic consistently exceeds the rated throughput. In such situations, the only solution is to limit the bandwidth by software means at the application level.

Configuration for PHY is described in `eth_phy_config_t`, including:

- `eth_phy_config_t::phy_addr`: multiple PHY devices can share the same SMI bus, so each PHY needs a unique address. Usually, this address is configured during hardware design by pulling up/down some PHY strapping pins. You can set the value from `0` to `15` based on your Ethernet board. Especially, if the SMI bus is shared by only one PHY device, setting this value to `-1` can enable the driver to detect the PHY address automatically.

- `eth_phy_config_t::reset_timeout_ms`: reset timeout value, in milliseconds. Typically, PHY reset should be finished within 100 ms.

- `eth_phy_config_t::autonego_timeout_ms`: auto-negotiation timeout value, in milliseconds. The Ethernet driver starts negotiation with the peer Ethernet node automatically, to determine to duplex and speed mode. This value usually depends on the ability of the PHY device on your board.

- `eth_phy_config_t::reset_gpio_num`: if your board also connects the PHY reset pin to one of the GPIO, then set it here. Otherwise, set this field to `-1`.

- `eth_phy_config_t::hw_reset_assert_time_us`: Time the PHY reset pin is asserted in usec. Set this field to `0` to use chip specific default timing.

- `eth_phy_config_t::post_hw_reset_delay_ms`: Time to wait after the PHY hardware reset is done in msec. Set this field to `0` to use chip specific default timing. Set this field to `-1` to not wait after the PHY hardware reset.

ESP-IDF provides a default configuration for MAC and PHY in macro `ETH_MAC_DEFAULT_CONFIG` and `ETH_PHY_DEFAULT_CONFIG`.

## Create MAC and PHY Instance

The Ethernet driver is implemented in an Object-Oriented style. Any operation on MAC and PHY should be based on the instance of the two.

### Internal EMAC + External PHY

    eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();                      // apply default common MAC configuration
    eth_esp32_emac_config_t esp32_emac_config = ETH_ESP32_EMAC_DEFAULT_CONFIG(); // apply default vendor-specific MAC configuration
    esp32_emac_config.smi_gpio.mdc_num = CONFIG_ETHERNET_MDC_GPIO;               // alter the GPIO used for MDC signal
    esp32_emac_config.smi_gpio.mdio_num = CONFIG_ETHERNET_MDIO_GPIO;             // alter the GPIO used for MDIO signal
    esp_eth_mac_t *mac = esp_eth_mac_new_esp32(&esp32_emac_config, &mac_config); // create MAC instance

    eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();      // apply default PHY configuration
    phy_config.phy_addr = CONFIG_ETHERNET_PHY_ADDR;              // alter the PHY address according to your board design
    phy_config.reset_gpio_num = CONFIG_ETHERNET_PHY_RST_GPIO;    // alter the GPIO used for PHY reset
    esp_eth_phy_t *phy = esp_eth_phy_new_generic(&phy_config);   // create generic PHY instance

Note

Any Ethernet PHY chip compliant with IEEE 802.3 can be used when creating new PHY instance with `esp_eth_phy_new_generic()`. However, while basic functionality should always work, some specific features might be limited, even if the PHY meets IEEE 802.3 standard. A typical example is loopback functionality, where certain PHYs may require setting a specific speed mode to operate correctly. If this is the concern and you need PHY driver specifically tailored to your chip needs, use drivers for PHY chips the ESP-IDF already officially supports or consult with Custom PHY Driver section to create a new custom driver.

Tip

Espressif provides drivers for several specific Ethernet PHY chips in the esp-eth-drivers repository. Drivers are distributed as components and are available in the ESP Component Registry.

### Optional Runtime MAC Clock Configuration

EMAC `REF_CLK` can be optionally configured from the user application code.

    eth_esp32_emac_config_t esp32_emac_config = ETH_ESP32_EMAC_DEFAULT_CONFIG(); // apply default vendor-specific MAC configuration

    // ...

    esp32_emac_config.interface = EMAC_DATA_INTERFACE_RMII;                      // alter EMAC Data Interface
    esp32_emac_config.clock_config.rmii.clock_mode = EMAC_CLK_OUT;               // select EMAC REF_CLK mode
    esp32_emac_config.clock_config.rmii.clock_gpio = 17;                         // select GPIO number used to input/output EMAC REF_CLK
    esp_eth_mac_t *mac = esp_eth_mac_new_esp32(&esp32_emac_config, &mac_config); // create MAC instance

### SPI-Ethernet Module

    eth_mac_config_t mac_config = ETH_MAC_DEFAULT_CONFIG();      // apply default common MAC configuration
    eth_phy_config_t phy_config = ETH_PHY_DEFAULT_CONFIG();      // apply default PHY configuration
    phy_config.phy_addr = CONFIG_ETHERNET_PHY_ADDR;              // alter the PHY address according to your board design
    phy_config.reset_gpio_num = CONFIG_ETHERNET_PHY_RST_GPIO;    // alter the GPIO used for PHY reset
    // Install GPIO interrupt service (as the SPI-Ethernet module is interrupt-driven)
    gpio_install_isr_service(0);
    // SPI bus configuration
    spi_device_handle_t spi_handle = NULL;
    spi_bus_config_t buscfg = {
        .miso_io_num = CONFIG_ETHERNET_SPI_MISO_GPIO,
        .mosi_io_num = CONFIG_ETHERNET_SPI_MOSI_GPIO,
        .sclk_io_num = CONFIG_ETHERNET_SPI_SCLK_GPIO,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
    };
    ESP_ERROR_CHECK(spi_bus_initialize(CONFIG_ETHERNET_SPI_HOST, &buscfg, 1));
    // Configure SPI device
    spi_device_interface_config_t spi_devcfg = {
        .mode = 0,
        .clock_speed_hz = CONFIG_ETHERNET_SPI_CLOCK_MHZ * 1000 * 1000,
        .spics_io_num = CONFIG_ETHERNET_SPI_CS_GPIO,
        .queue_size = 20
    };
    /* dm9051 ethernet driver is based on spi driver */
    eth_dm9051_config_t dm9051_config = ETH_DM9051_DEFAULT_CONFIG(CONFIG_ETHERNET_SPI_HOST, &spi_devcfg);
    dm9051_config.int_gpio_num = CONFIG_ETHERNET_SPI_INT_GPIO;
    esp_eth_mac_t *mac = esp_eth_mac_new_dm9051(&dm9051_config, &mac_config);
    esp_eth_phy_t *phy = esp_eth_phy_new_dm9051(&phy_config);

Note

- When creating MAC and PHY instances for SPI-Ethernet modules (e.g., DM9051), the constructor function must have the same suffix (e.g., esp_eth_mac_new_dm9051 and esp_eth_phy_new_dm9051). This is because we don not have other choices but the integrated PHY.

- The SPI device configuration (i.e., spi_device_interface_config_t) may slightly differ for other Ethernet modules or to meet SPI timing on specific PCB. Please check out your module's specs and the examples in ESP-IDF.

Tip

Espressif provides drivers for various SPI-Ethernet modules in the esp-eth-drivers repository. Drivers are distributed as components and are available in the ESP Component Registry.

## Install Driver

To install the Ethernet driver, we need to combine the instance of MAC and PHY and set some additional high-level configurations (i.e., not specific to either MAC or PHY) in `esp_eth_config_t`:

- `esp_eth_config_t::mac`: instance that created from MAC generator (e.g., `esp_eth_mac_new_esp32()`).

- `esp_eth_config_t::phy`: instance that created from PHY generator (e.g., `esp_eth_phy_new_generic()`).

- `esp_eth_config_t::check_link_period_ms`: Ethernet driver starts an OS timer to check the link status periodically, this field is used to set the interval, in milliseconds.

- `esp_eth_config_t::stack_input` or `esp_eth_config_t::stack_input_info`: In most Ethernet IoT applications, any Ethernet frame received by a driver should be passed to the upper layer (e.g., TCP/IP stack). This field is set to a function that is responsible to deal with the incoming frames. You can even update this field at runtime via function `esp_eth_update_input_path()` after driver installation.

- `esp_eth_config_t::on_lowlevel_init_done` and `esp_eth_config_t::on_lowlevel_deinit_done`: These two fields are used to specify the hooks which get invoked when low-level hardware has been initialized or de-initialized.

ESP-IDF provides a default configuration for driver installation in macro `ETH_DEFAULT_CONFIG`.

    esp_eth_config_t config = ETH_DEFAULT_CONFIG(mac, phy); // apply default driver configuration
    esp_eth_handle_t eth_handle = NULL; // after the driver is installed, we will get the handle of the driver
    esp_eth_driver_install(&config, &eth_handle); // install driver

The Ethernet driver also includes an event-driven model, which sends useful and important events to user space. We need to initialize the event loop before installing the Ethernet driver. For more information about event-driven programming, please refer to ESP Event.

    /** Event handler for Ethernet events */
    static void eth_event_handler(void *arg, esp_event_base_t event_base,
                                  int32_t event_id, void *event_data)
    {
        uint8_t mac_addr[6] = {0};
        /* we can get the ethernet driver handle from event data */
        esp_eth_handle_t eth_handle = *(esp_eth_handle_t *)event_data;

        switch (event_id) {
        case ETHERNET_EVENT_CONNECTED:
            esp_eth_ioctl(eth_handle, ETH_CMD_G_MAC_ADDR, mac_addr);
            ESP_LOGI(TAG, "Ethernet Link Up");
            ESP_LOGI(TAG, "Ethernet HW Addr %02x:%02x:%02x:%02x:%02x:%02x",
                        mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
            break;
        case ETHERNET_EVENT_DISCONNECTED:
            ESP_LOGI(TAG, "Ethernet Link Down");
            break;
        case ETHERNET_EVENT_START:
            ESP_LOGI(TAG, "Ethernet Started");
            break;
        case ETHERNET_EVENT_STOP:
            ESP_LOGI(TAG, "Ethernet Stopped");
            break;
        default:
            break;
        }
    }

    esp_event_loop_create_default(); // create a default event loop that runs in the background
    esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, &eth_event_handler, NULL); // register Ethernet event handler (to deal with user-specific stuff when events like link up/down happened)

## Start Ethernet Driver

After driver installation, we can start Ethernet immediately.

    esp_eth_start(eth_handle); // start Ethernet driver state machine

## Connect Driver to TCP/IP Stack

Up until now, we have installed the Ethernet driver. From the view of OSI (Open System Interconnection), we are still on level 2 (i.e., Data Link Layer). While we can detect link up and down events and gain MAC address in user space, it is infeasible to obtain the IP address, let alone send an HTTP request. The TCP/IP stack used in ESP-IDF is called LwIP. For more information about it, please refer to LwIP.

To connect the Ethernet driver to TCP/IP stack, follow these three steps:

1. Create a network interface for the Ethernet driver

2. Attach the network interface to the Ethernet driver

3. Register IP event handlers

For more information about the network interface, please refer to Network Interface.

    /** Event handler for IP_EVENT_ETH_GOT_IP */
    static void got_ip_event_handler(void *arg, esp_event_base_t event_base,
                                     int32_t event_id, void *event_data)
    {
        ip_event_got_ip_t *event = (ip_event_got_ip_t *) event_data;
        const esp_netif_ip_info_t *ip_info = &event->ip_info;

        ESP_LOGI(TAG, "Ethernet Got IP Address");
        ESP_LOGI(TAG, "~~~~~~~~~~~");
        ESP_LOGI(TAG, "ETHIP:" IPSTR, IP2STR(&ip_info->ip));
        ESP_LOGI(TAG, "ETHMASK:" IPSTR, IP2STR(&ip_info->netmask));
        ESP_LOGI(TAG, "ETHGW:" IPSTR, IP2STR(&ip_info->gw));
        ESP_LOGI(TAG, "~~~~~~~~~~~");
    }

    esp_netif_init()); // Initialize TCP/IP network interface (should be called only once in application)
    esp_netif_config_t cfg = ESP_NETIF_DEFAULT_ETH(); // apply default network interface configuration for Ethernet
    esp_netif_t *eth_netif = esp_netif_new(&cfg); // create network interface for Ethernet driver

    esp_netif_attach(eth_netif, esp_eth_new_netif_glue(eth_handle)); // attach Ethernet driver to TCP/IP stack
    esp_event_handler_register(IP_EVENT, IP_EVENT_ETH_GOT_IP, &got_ip_event_handler, NULL); // register user defined IP event handlers
    esp_eth_start(eth_handle); // start Ethernet driver state machine

Warning

It is recommended to fully initialize the Ethernet driver and network interface before registering the user's Ethernet/IP event handlers, i.e., register the event handlers as the last thing prior to starting the Ethernet driver. Such an approach ensures that Ethernet/IP events get executed first by the Ethernet driver or network interface so the system is in the expected state when executing the user's handlers.

## Misc Control of Ethernet Driver

The following functions should only be invoked after the Ethernet driver has been installed.

- Stop Ethernet driver: `esp_eth_stop()`

- Update Ethernet data input path: `esp_eth_update_input_path()`

- Misc get/set of Ethernet driver attributes: `esp_eth_ioctl()`

    /* get MAC address */
    uint8_t mac_addr[6];
    memset(mac_addr, 0, sizeof(mac_addr));
    esp_eth_ioctl(eth_handle, ETH_CMD_G_MAC_ADDR, mac_addr);
    ESP_LOGI(TAG, "Ethernet MAC Address: %02x:%02x:%02x:%02x:%02x:%02x",
             mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);

    /* get PHY address */
    int phy_addr = -1;
    esp_eth_ioctl(eth_handle, ETH_CMD_G_PHY_ADDR, &phy_addr);
    ESP_LOGI(TAG, "Ethernet PHY Address: %d", phy_addr);

## Flow Control

Ethernet on MCU usually has a limitation in the number of frames it can handle during network congestion, because of the limitation in RAM size. A sending station might be transmitting data faster than the peer end can accept it. The ethernet flow control mechanism allows the receiving node to signal the sender requesting the suspension of transmissions until the receiver catches up. The magic behind that is the pause frame, which was defined in IEEE 802.3x.

Pause frame is a special Ethernet frame used to carry the pause command, whose EtherType field is `0x8808`, with the Control opcode set to `0x0001`. Only stations configured for full-duplex operation may send pause frames. When a station wishes to pause the other end of a link, it sends a pause frame to the 48-bit reserved multicast address of `01-80-C2-00-00-01`. The pause frame also includes the period of pause time being requested, in the form of a two-byte integer, ranging from `0` to `65535`.

After the Ethernet driver installation, the flow control feature is disabled by default. You can enable it by:

    bool flow_ctrl_enable = true;
    esp_eth_ioctl(eth_handle, ETH_CMD_S_FLOW_CTRL, &flow_ctrl_enable);

One thing that should be kept in mind is that the pause frame ability is advertised to the peer end by PHY during auto-negotiation. The Ethernet driver sends a pause frame only when both sides of the link support it.

## Application Examples

> - ethernet/basic demonstrates how to use the Ethernet driver, covering driver installation, attaching it to esp_netif, sending DHCP requests, and obtaining a pingable IP address.

> - ethernet/iperf demonstrates how to use the Ethernet capabilities to measure the throughput/bandwidth using iPerf.

> - ethernet/ptp demonstrates the use of Precision Time Protocol (PTP) for time synchronization over Ethernet.

> - network/vlan_support demonstrates how to create virtual network interfaces over Ethernet, including VLAN and non-VLAN interfaces.

> - network/sta2eth demonstrates how to create a 1-to-1 bridge using a Wi-Fi station and a wired interface such as Ethernet or USB.

> - network/simple_sniffer demonstrates how to use Wi-Fi and Ethernet in sniffer mode to capture packets and save them in PCAP format.

> - network/eth2ap demonstrates how to implement a bridge that forwards packets between an Ethernet port and a Wi-Fi AP interface. It uses ESP32 to create a 1-to-many connection between Ethernet and Wi-Fi without initializing the TCP/IP stack.

> - network/bridge demonstrates how to use the LwIP IEEE 802.1D bridge to forward Ethernet frames between multiple network segments based on MAC addresses.

> - Most protocol examples should also work for Ethernet: protocols.

## Advanced Topics

### Custom PHY Driver

There are multiple PHY manufacturers with wide portfolios of chips available. The ESP-IDF supports `Generic PHY` and also several specific PHY chips however one can easily get to a point where none of them satisfies the user's actual needs due to price, features, stock availability, etc.

Luckily, a management interface between EMAC and PHY is standardized by IEEE 802.3 in Section 22.2.4 Management Functions. It defines provisions of the so-called "MII Management Interface" to control the PHY and gather status from the PHY. A set of management registers is defined to control chip behavior, link properties, auto-negotiation configuration, etc. This basic management functionality is addressed by esp_eth/src/phy/esp_eth_phy_802_3.c in ESP-IDF and so it makes the creation of a new custom PHY chip driver quite a simple task.

Note

Always consult with PHY datasheet since some PHY chips may not comply with IEEE 802.3, Section 22.2.4. It does not mean you are not able to create a custom PHY driver, but it just requires more effort. You will have to define all PHY management functions.

The majority of PHY management functionality required by the ESP-IDF Ethernet driver is covered by the esp_eth/src/phy/esp_eth_phy_802_3.c. However, the following may require developing chip-specific management functions:

> - Link status which is almost always chip-specific

> - Chip initialization, even though not strictly required, should be customized to at least ensure that the expected chip is used

> - Chip-specific features configuration

Steps to create a custom PHY driver:

1. Define vendor-specific registry layout based on the PHY datasheet.

2. Prepare derived PHY management object info structure which:

   > - must contain at least parent IEEE 802.3 `phy_802_3_t` object

   > - optionally contain additional variables needed to support non-IEEE 802.3 or customized functionality.

3. Define chip-specific management call-back functions.

4. Initialize parent IEEE 802.3 object and re-assign chip-specific management call-back functions.

Once you finish the new custom PHY driver implementation, consider sharing it among other users via ESP Component Registry.

## API Reference

### Header File

- components/esp_hal_emac/include/hal/eth_types.h

- This header file can be included with:

  >     #include "hal/eth_types.h"

- This header file is a part of the API provided by the `esp_hal_emac` component. To declare that your component depends on `esp_hal_emac`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_hal_emac

  > or

  >     PRIV_REQUIRES esp_hal_emac

### Enumerations

enum eth_data_interface_t

  Ethernet interface.

  Values:

  enumerator EMAC_DATA_INTERFACE_RMII

    Reduced Media Independent Interface

  enumerator EMAC_DATA_INTERFACE_MII

    Media Independent Interface

  enumerator EMAC_DATA_INTERFACE_RGMII

    Reduced Gigabit Media Independent Interface

enum eth_link_t

  Ethernet link status.

  Values:

  enumerator ETH_LINK_UP

    Ethernet link is up

  enumerator ETH_LINK_DOWN

    Ethernet link is down

enum eth_speed_t

  Ethernet speed.

  Values:

  enumerator ETH_SPEED_10M

    Ethernet speed is 10Mbps

  enumerator ETH_SPEED_100M

    Ethernet speed is 100Mbps

  enumerator ETH_SPEED_1000M

    Ethernet speed is 1000Mbps

  enumerator ETH_SPEED_MAX

    Max speed mode (for checking purpose)

enum eth_duplex_t

  Ethernet duplex mode.

  Values:

  enumerator ETH_DUPLEX_HALF

    Ethernet is in half duplex

  enumerator ETH_DUPLEX_FULL

    Ethernet is in full duplex

enum eth_checksum_t

  Ethernet Checksum.

  Values:

  enumerator ETH_CHECKSUM_SW

    Ethernet checksum calculate by software

  enumerator ETH_CHECKSUM_HW

    Ethernet checksum calculate by hardware

enum eth_mac_dma_burst_len_t

  Internal ethernet EMAC's DMA available burst sizes.

  Values:

  enumerator ETH_DMA_BURST_LEN_32
  enumerator ETH_DMA_BURST_LEN_16
  enumerator ETH_DMA_BURST_LEN_8
  enumerator ETH_DMA_BURST_LEN_4
  enumerator ETH_DMA_BURST_LEN_2
  enumerator ETH_DMA_BURST_LEN_1

enum eth_mac_ptp_update_method_t

  EMAC System timestamp update update method.

  Values:

  enumerator ETH_PTP_UPDATE_METHOD_COARSE

    EMAC System timestamp update using the Coarse method

  enumerator ETH_PTP_UPDATE_METHOD_FINE

    EMAC System timestamp update using the Fine method

enum eth_mac_ptp_roll_type_t

  EMAC System Timestamp Rollover.

  Values:

  enumerator ETH_PTP_DIGITAL_ROLLOVER

    Digital - subseconds register rolls over after 999999999 value (1 nanosecond accuracy)

  enumerator ETH_PTP_BINARY_ROLLOVER

    Binary - subseconds register rolls over after 0x7FFFFFFF value

enum eth_pad_t

  EMAC System dedicated pad identifier.

  Values:

  enumerator ETH_PAD_RMII_CLK
  enumerator ETH_PAD_RX_CLK
  enumerator ETH_PAD_PHY_RXDV
  enumerator ETH_PAD_PHY_RXD3
  enumerator ETH_PAD_PHY_RXD2
  enumerator ETH_PAD_PHY_RXD1
  enumerator ETH_PAD_PHY_RXD0
  enumerator ETH_PAD_TX_CLK
  enumerator ETH_PAD_PHY_TXEN
  enumerator ETH_PAD_PHY_TXD3
  enumerator ETH_PAD_PHY_TXD2
  enumerator ETH_PAD_PHY_TXD1
  enumerator ETH_PAD_PHY_TXD0

### Header File

- components/esp_eth/include/esp_eth.h

- This header file can be included with:

  >     #include "esp_eth.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Header File

- components/esp_eth/include/esp_eth_driver.h

- This header file can be included with:

  >     #include "esp_eth_driver.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Functions

esp_err_t esp_eth_driver_install(const esp_eth_config_t *config, esp_eth_handle_t *out_hdl)

  Install Ethernet driver.

  Parameters:

    - config -- [in] configuration of the Ethernet driver

    - out_hdl -- [out] handle of Ethernet driver

  Returns:

    - ESP_OK: install esp_eth driver successfully

    - ESP_ERR_INVALID_ARG: install esp_eth driver failed because of some invalid argument

    - ESP_ERR_NO_MEM: install esp_eth driver failed because there's no memory for driver

    - ESP_FAIL: install esp_eth driver failed because some other error occurred

esp_err_t esp_eth_driver_uninstall(esp_eth_handle_t hdl)

  Uninstall Ethernet driver.

  Note

  It's not recommended to uninstall Ethernet driver unless it won't get used any more in application code. To uninstall Ethernet driver, you have to make sure, all references to the driver are released. Ethernet driver can only be uninstalled successfully when reference counter equals to one.

  Parameters:

    hdl -- [in] handle of Ethernet driver

  Returns:

    - ESP_OK: uninstall esp_eth driver successfully

    - ESP_ERR_INVALID_ARG: uninstall esp_eth driver failed because of some invalid argument

    - ESP_ERR_INVALID_STATE: uninstall esp_eth driver failed because it has more than one reference

    - ESP_FAIL: uninstall esp_eth driver failed because some other error occurred

esp_err_t esp_eth_start(esp_eth_handle_t hdl)

  Start Ethernet driver ONLY in standalone mode (i.e. without TCP/IP stack)

  Note

  This API will start driver state machine and internal software timer (for checking link status).

  Parameters:

    hdl -- [in] handle of Ethernet driver

  Returns:

    - ESP_OK: start esp_eth driver successfully

    - ESP_ERR_INVALID_ARG: start esp_eth driver failed because of some invalid argument

    - ESP_ERR_INVALID_STATE: start esp_eth driver failed because driver has started already

    - ESP_FAIL: start esp_eth driver failed because some other error occurred

esp_err_t esp_eth_stop(esp_eth_handle_t hdl)

  Stop Ethernet driver.

  Note

  This function does the opposite operation of `esp_eth_start`.

  Parameters:

    hdl -- [in] handle of Ethernet driver

  Returns:

    - ESP_OK: stop esp_eth driver successfully

    - ESP_ERR_INVALID_ARG: stop esp_eth driver failed because of some invalid argument

    - ESP_ERR_INVALID_STATE: stop esp_eth driver failed because driver has not started yet

    - ESP_FAIL: stop esp_eth driver failed because some other error occurred

esp_err_t esp_eth_update_input_path(esp_eth_handle_t hdl, esp_err_t (*stack_input)(esp_eth_handle_t hdl, uint8_t *buffer, uint32_t length, void *priv), void *priv)

  Update Ethernet data input path (i.e. specify where to pass the input buffer)

  Note

  After install driver, Ethernet still don't know where to deliver the input buffer. In fact, this API registers a callback function which get invoked when Ethernet received new packets.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - stack_input -- [in] function pointer, which does the actual process on incoming packets

    - priv -- [in] private resource, which gets passed to `stack_input` callback without any modification

  Returns:

    - ESP_OK: update input path successfully

    - ESP_ERR_INVALID_ARG: update input path failed because of some invalid argument

    - ESP_FAIL: update input path failed because some other error occurred

esp_err_t esp_eth_update_input_path_info(esp_eth_handle_t hdl, esp_err_t (*stack_input_info)(esp_eth_handle_t hdl, uint8_t *buffer, uint32_t length, void *priv, void *info), void *priv)

  Update Ethernet data input path with input function which consumes extra info about received frame.

  Note

  Extra information may include but is not limited to such info like Time Stamp, CRC check offload result, etc. The MAC layer of the Ethernet driver of the particular device must provide extra information using `stack_input_info()` function. Otherwise, input path function registered by this API is not invoked. If this is the case, register `stack_input` function by `esp_eth_update_input_path()` instead.

  Note

  After install driver, Ethernet still don't know where to deliver the input buffer. In fact, this API registers a callback function which get invoked when Ethernet received new packets.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - stack_input_info -- [in] function pointer, which does the actual process on incoming packets

    - priv -- [in] private resource, which gets passed to `stack_input_info` callback without any modification

  Returns:

    - ESP_OK: update input path successfully

    - ESP_ERR_INVALID_ARG: update input path failed because of some invalid argument

    - ESP_FAIL: update input path failed because some other error occurred

esp_err_t esp_eth_transmit(esp_eth_handle_t hdl, void *buf, size_t length)

  General Transmit.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - buf -- [in] buffer of the packet to transfer

    - length -- [in] length of the buffer to transfer

  Returns:

    - ESP_OK: transmit frame buffer successfully

    - ESP_ERR_INVALID_ARG: transmit frame buffer failed because of some invalid argument

    - ESP_ERR_INVALID_STATE: invalid driver state (e.i., driver is not started)

    - ESP_ERR_TIMEOUT: transmit frame buffer failed because HW was not get available in predefined period

    - ESP_FAIL: transmit frame buffer failed because some other error occurred

esp_err_t esp_eth_transmit_ctrl_vargs(esp_eth_handle_t hdl, void *ctrl, uint32_t argc, ...)

  Extended Transmit with variable number of arguments.

  Note

  Typical intended use case of this function is to assemble Ethernet frame from multiple input buffers at lower layer of the driver (MAC layer) to avoid unnecessary buffer reallocation and copy.

  Parameters:

    - hdl -- handle of Ethernet driver

    - ctrl -- optional transmit control structure (MAC specific), set to NULL when not required

    - argc -- number variable arguments

    - ... -- variable arguments

  Returns:

    - ESP_OK: transmit successful

    - ESP_ERR_INVALID_STATE: invalid driver state (e.i., driver is not started)

    - ESP_ERR_TIMEOUT: transmit frame buffer failed because HW was not get available in predefined period

    - ESP_FAIL: transmit frame buffer failed because some other error occurred

esp_err_t esp_eth_ioctl(esp_eth_handle_t hdl, esp_eth_io_cmd_t cmd, void *data)

  Misc IO function of Ethernet driver.

  The following common IO control commands are supported:

  - `ETH_CMD_S_MAC_ADDR` sets Ethernet interface MAC address. `data` argument is pointer to MAC address buffer with expected size of 6 bytes.

  - `ETH_CMD_G_MAC_ADDR` gets Ethernet interface MAC address. `data` argument is pointer to a buffer to which MAC address is to be copied. The buffer size must be at least 6 bytes.

  - `ETH_CMD_S_PHY_ADDR` sets PHY address in range of <0-31>. `data` argument is pointer to memory of uint32_t datatype from where the configuration option is read.

  - `ETH_CMD_G_PHY_ADDR` gets PHY address. `data` argument is pointer to memory of uint32_t datatype to which the PHY address is to be stored.

  - `ETH_CMD_S_AUTONEGO` enables or disables Ethernet link speed and duplex mode autonegotiation. `data` argument is pointer to memory of bool datatype from which the configuration option is read. Preconditions: Ethernet driver needs to be stopped.

  - `ETH_CMD_G_AUTONEGO` gets current configuration of the Ethernet link speed and duplex mode autonegotiation. `data` argument is pointer to memory of bool datatype to which the current configuration is to be stored.

  - `ETH_CMD_S_SPEED` sets the Ethernet link speed. `data` argument is pointer to memory of eth_speed_t datatype from which the configuration option is read. Preconditions: Ethernet driver needs to be stopped and auto-negotiation disabled.

  - `ETH_CMD_G_SPEED` gets current Ethernet link speed. `data` argument is pointer to memory of eth_speed_t datatype to which the speed is to be stored.

  - `ETH_CMD_S_PROMISCUOUS` sets/resets Ethernet interface promiscuous mode. `data` argument is pointer to memory of bool datatype from which the configuration option is read.

  - `ETH_CMD_S_FLOW_CTRL` sets/resets Ethernet interface flow control. `data` argument is pointer to memory of bool datatype from which the configuration option is read.

  - `ETH_CMD_S_DUPLEX_MODE` sets the Ethernet duplex mode. `data` argument is pointer to memory of eth_duplex_t datatype from which the configuration option is read. Preconditions: Ethernet driver needs to be stopped and auto-negotiation disabled.

  - `ETH_CMD_G_DUPLEX_MODE` gets current Ethernet link duplex mode. `data` argument is pointer to memory of eth_duplex_t datatype to which the duplex mode is to be stored.

  - `ETH_CMD_S_PHY_LOOPBACK` sets/resets PHY to/from loopback mode. `data` argument is pointer to memory of bool datatype from which the configuration option is read.

  - `ETH_CMD_S_ALL_MULTICAST` sets/resets Ethernet interface to/from receive all multicast mode. `data` argument is pointer to memory of bool datatype from which the configuration option is read.

  - `ETH_CMD_ADD_MAC_FILTER` adds a MAC address to the MAC filter. `data` argument is pointer to MAC address buffer with expected size of 6 bytes.

  - `ETH_CMD_DEL_MAC_FILTER` deletes a MAC address from the MAC filter. `data` argument is pointer to MAC address buffer with expected size of 6 bytes.

  - Note that additional control commands may be available for specific MAC or PHY chips. Please consult specific MAC or PHY documentation or driver code.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - cmd -- [in] IO control command

    - data -- [inout] address of data for `set` command or address where to store the data when used with `get` command

  Returns:

    - ESP_OK: process io command successfully

    - ESP_ERR_INVALID_ARG: process io command failed because of some invalid argument

    - ESP_FAIL: process io command failed because some other error occurred

    - ESP_ERR_NOT_SUPPORTED: requested feature is not supported

esp_err_t esp_eth_get_phy_instance(esp_eth_handle_t hdl, esp_eth_phy_t **phy)

  Get PHY instance memory address.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - phy -- [out] pointer to memory to store the instance

  Returns:

    esp_err_t

    - ESP_OK: success

    - ESP_ERR_INVALID_ARG: failed because of some invalid argument

esp_err_t esp_eth_get_mac_instance(esp_eth_handle_t hdl, esp_eth_mac_t **mac)

  Get MAC instance memory address.

  Parameters:

    - hdl -- [in] handle of Ethernet driver

    - mac -- [out] pointer to memory to store the instance

  Returns:

    esp_err_t

    - ESP_OK: success

    - ESP_ERR_INVALID_ARG: failed because of some invalid argument

esp_err_t esp_eth_increase_reference(esp_eth_handle_t hdl)

  Increase Ethernet driver reference.

  Note

  Ethernet driver handle can be obtained by os timer, netif, etc. It's dangerous when thread A is using Ethernet but thread B uninstall the driver. Using reference counter can prevent such risk, but care should be taken, when you obtain Ethernet driver, this API must be invoked so that the driver won't be uninstalled during your using time.

  Parameters:

    hdl -- [in] handle of Ethernet driver

  Returns:

    - ESP_OK: increase reference successfully

    - ESP_ERR_INVALID_ARG: increase reference failed because of some invalid argument

esp_err_t esp_eth_decrease_reference(esp_eth_handle_t hdl)

  Decrease Ethernet driver reference.

  Parameters:

    hdl -- [in] handle of Ethernet driver

  Returns:

    - ESP_OK: increase reference successfully

    - ESP_ERR_INVALID_ARG: increase reference failed because of some invalid argument

### Structures

struct esp_eth_config_t

  Configuration of Ethernet driver.

  Public Members

  esp_eth_mac_t *mac

    Ethernet MAC object.

  esp_eth_phy_t *phy

    Ethernet PHY object.

  uint32_t check_link_period_ms

    Period time of checking Ethernet link status.

  esp_err_t (*stack_input)(esp_eth_handle_t eth_handle, uint8_t *buffer, uint32_t length, void *priv)

    Input frame buffer to user's stack.

    Param eth_handle:

      [in] handle of Ethernet driver

    Param buffer:

      [in] frame buffer that will get input to upper stack

    Param length:

      [in] length of the frame buffer

    Param priv:

      [in] pointer to private resource, defined when registering the input function

    Return:

      - ESP_OK: input frame buffer to upper stack successfully

      - ESP_FAIL: error occurred when inputting buffer to upper stack

  esp_err_t (*stack_input_info)(esp_eth_handle_t eth_handle, uint8_t *buffer, uint32_t length, void *priv, void *info)

    Input frame buffer to user's stack with additional information about received frame.

    Param eth_handle:

      [in] handle of Ethernet driver

    Param buffer:

      [in] frame buffer that will get input to upper stack

    Param length:

      [in] length of the frame buffer

    Param priv:

      [in] pointer to private resource, defined when registering the input function

    Param info:

      [in] extra information about received Ethernet frame (may be timestamp, CRC offload check result, etc.)

    Return:

      - ESP_OK: input frame buffer to upper stack successfully

      - ESP_FAIL: error occurred when inputting buffer to upper stack

  esp_err_t (*on_lowlevel_init_done)(esp_eth_handle_t eth_handle)

    Callback function invoked when lowlevel initialization is finished.

    Param eth_handle:

      [in] handle of Ethernet driver

    Return:

      - ESP_OK: process extra lowlevel initialization successfully

      - ESP_FAIL: error occurred when processing extra lowlevel initialization

  esp_err_t (*on_lowlevel_deinit_done)(esp_eth_handle_t eth_handle)

    Callback function invoked when lowlevel deinitialization is finished.

    Param eth_handle:

      [in] handle of Ethernet driver

    Return:

      - ESP_OK: process extra lowlevel deinitialization successfully

      - ESP_FAIL: error occurred when processing extra lowlevel deinitialization

  esp_err_t (*read_phy_reg)(esp_eth_handle_t eth_handle, uint32_t phy_addr, uint32_t phy_reg, uint32_t *reg_value)

    Read PHY register.

    Note

    Usually the PHY register read/write function is provided by MAC (SMI interface), but if the PHY device is managed by other interface (e.g. I2C), then user needs to implement the corresponding read/write. Setting this to NULL means your PHY device is managed by MAC's SMI interface.

    Param eth_handle:

      [in] handle of Ethernet driver

    Param phy_addr:

      [in] PHY chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [out] PHY register value

    Return:

      - ESP_OK: read PHY register successfully

      - ESP_ERR_INVALID_ARG: read PHY register failed because of invalid argument

      - ESP_ERR_TIMEOUT: read PHY register failed because of timeout

      - ESP_FAIL: read PHY register failed because some other error occurred

  esp_err_t (*write_phy_reg)(esp_eth_handle_t eth_handle, uint32_t phy_addr, uint32_t phy_reg, uint32_t reg_value)

    Write PHY register.

    Note

    Usually the PHY register read/write function is provided by MAC (SMI interface), but if the PHY device is managed by other interface (e.g. I2C), then user needs to implement the corresponding read/write. Setting this to NULL means your PHY device is managed by MAC's SMI interface.

    Param eth_handle:

      [in] handle of Ethernet driver

    Param phy_addr:

      [in] PHY chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [in] PHY register value

    Return:

      - ESP_OK: write PHY register successfully

      - ESP_ERR_INVALID_ARG: read PHY register failed because of invalid argument

      - ESP_ERR_TIMEOUT: write PHY register failed because of timeout

      - ESP_FAIL: write PHY register failed because some other error occurred

struct esp_eth_phy_reg_rw_data_t

  Data structure to Read/Write PHY register via ioctl API.

  Public Members

  uint32_t reg_addr

    PHY register address

  uint32_t *reg_value_p

    Pointer to a memory where the register value is read/written

### Macros

ETH_DEFAULT_CONFIG(emac, ephy)

  Default configuration for Ethernet driver.

esp_eth_transmit_vargs(eth_hdl, argc, ...)

  Wrapper over Extended Transmit function to ensure backward compatibility.

  Note

  For new implementations, it is recommended to use `esp_eth_transmit_ctrl_vargs()` directly.

  Parameters:

    - eth_hdl -- [in] handle of Ethernet driver

    - argc -- [in] number variable arguments

    - ... -- variable arguments

  Returns:

    - ESP_OK: transmit successful

    - ESP_ERR_INVALID_STATE: invalid driver state (e.i., driver is not started)

    - ESP_ERR_TIMEOUT: transmit frame buffer failed because HW was not get available in predefined period

    - ESP_FAIL: transmit frame buffer failed because some other error occurred

### Type Definitions

typedef void *esp_eth_handle_t

  Handle of Ethernet driver.

### Enumerations

enum esp_eth_io_cmd_t

  Command list for ioctl API.

  Values:

  enumerator ETH_CMD_G_MAC_ADDR

    Get MAC address

  enumerator ETH_CMD_S_MAC_ADDR

    Set MAC address

  enumerator ETH_CMD_G_PHY_ADDR

    Get PHY address

  enumerator ETH_CMD_S_PHY_ADDR

    Set PHY address

  enumerator ETH_CMD_G_AUTONEGO

    Get PHY Auto Negotiation

  enumerator ETH_CMD_S_AUTONEGO

    Set PHY Auto Negotiation

  enumerator ETH_CMD_G_SPEED

    Get Speed

  enumerator ETH_CMD_S_SPEED

    Set Speed

  enumerator ETH_CMD_S_PROMISCUOUS

    Set promiscuous mode

  enumerator ETH_CMD_S_FLOW_CTRL

    Set flow control

  enumerator ETH_CMD_G_DUPLEX_MODE

    Get Duplex mode

  enumerator ETH_CMD_S_DUPLEX_MODE

    Set Duplex mode

  enumerator ETH_CMD_S_PHY_LOOPBACK

    Set PHY loopback

  enumerator ETH_CMD_READ_PHY_REG

    Read PHY register

  enumerator ETH_CMD_WRITE_PHY_REG

    Write PHY register

  enumerator ETH_CMD_S_ALL_MULTICAST

    Set receive all multicast

  enumerator ETH_CMD_ADD_MAC_FILTER

    Add MAC filter

  enumerator ETH_CMD_DEL_MAC_FILTER

    Delete MAC filter

  enumerator ETH_CMD_CUSTOM_MAC_CMDS
  enumerator ETH_CMD_CUSTOM_PHY_CMDS

### Header File

- components/esp_eth/include/esp_eth_com.h

- This header file can be included with:

  >     #include "esp_eth_com.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Structures

struct esp_eth_mediator_s

  Ethernet mediator.

  Public Members

  esp_err_t (*phy_reg_read)(esp_eth_mediator_t *eth, uint32_t phy_addr, uint32_t phy_reg, uint32_t *reg_value)

    Read PHY register.

    Param eth:

      [in] mediator of Ethernet driver

    Param phy_addr:

      [in] PHY Chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [out] PHY register value

    Return:

      - ESP_OK: read PHY register successfully

      - ESP_FAIL: read PHY register failed because some error occurred

  esp_err_t (*phy_reg_write)(esp_eth_mediator_t *eth, uint32_t phy_addr, uint32_t phy_reg, uint32_t reg_value)

    Write PHY register.

    Param eth:

      [in] mediator of Ethernet driver

    Param phy_addr:

      [in] PHY Chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [in] PHY register value

    Return:

      - ESP_OK: write PHY register successfully

      - ESP_FAIL: write PHY register failed because some error occurred

  esp_err_t (*stack_input)(esp_eth_mediator_t *eth, uint8_t *buffer, uint32_t length)

    Deliver packet to upper stack.

    Param eth:

      [in] mediator of Ethernet driver

    Param buffer:

      [in] packet buffer

    Param length:

      [in] length of the packet

    Return:

      - ESP_OK: deliver packet to upper stack successfully

      - ESP_FAIL: deliver packet failed because some error occurred

  esp_err_t (*stack_input_info)(esp_eth_mediator_t *eth, uint8_t *buffer, uint32_t length, void *info)

    Deliver packet to upper stack with additional information about reception.

    Param eth:

      [in] mediator of Ethernet driver

    Param buffer:

      [in] packet buffer

    Param length:

      [in] length of the packet

    Param info:

      [in] info associated with reception (e.g. time stamp)

    Return:

      - ESP_OK: deliver packet to upper stack successfully

      - ESP_FAIL: deliver packet failed because some error occurred

  esp_err_t (*on_state_changed)(esp_eth_mediator_t *eth, esp_eth_state_t state, void *args)

    Callback on Ethernet state changed.

    Param eth:

      [in] mediator of Ethernet driver

    Param state:

      [in] new state

    Param args:

      [in] optional argument for the new state

    Return:

      - ESP_OK: process the new state successfully

      - ESP_FAIL: process the new state failed because some error occurred

### Macros

ETH_CMD_CUSTOM_MAC_CMDS_OFFSET

  Offset for start of MAC custom ioctl commands.

ETH_CMD_CUSTOM_PHY_CMDS_OFFSET

  Offset for start of PHY custom ioctl commands.

### Type Definitions

typedef struct esp_eth_mediator_s esp_eth_mediator_t

  Ethernet mediator.

### Enumerations

enum esp_eth_state_t

  Ethernet driver state.

  Values:

  enumerator ETH_STATE_LLINIT

    Lowlevel init done

  enumerator ETH_STATE_DEINIT

    Deinit done

  enumerator ETH_STATE_LINK

    Link status changed

  enumerator ETH_STATE_SPEED

    Speed updated

  enumerator ETH_STATE_DUPLEX

    Duplex updated

  enumerator ETH_STATE_PAUSE

    Pause ability updated

enum eth_event_t

  Ethernet event declarations.

  Values:

  enumerator ETHERNET_EVENT_START

    Ethernet driver start

  enumerator ETHERNET_EVENT_STOP

    Ethernet driver stop

  enumerator ETHERNET_EVENT_CONNECTED

    Ethernet got a valid link

  enumerator ETHERNET_EVENT_DISCONNECTED

    Ethernet lost a valid link

### Header File

- components/esp_eth/include/esp_eth_mac.h

- This header file can be included with:

  >     #include "esp_eth_mac.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Structures

struct esp_eth_mac_s

  Ethernet MAC.

  Public Members

  esp_err_t (*set_mediator)(esp_eth_mac_t *mac, esp_eth_mediator_t *eth)

    Set mediator for Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Param eth:

      [in] Ethernet mediator

    Return:

      - ESP_OK: set mediator for Ethernet MAC successfully

      - ESP_ERR_INVALID_ARG: set mediator for Ethernet MAC failed because of invalid argument

  esp_err_t (*init)(esp_eth_mac_t *mac)

    Initialize Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Return:

      - ESP_OK: initialize Ethernet MAC successfully

      - ESP_ERR_TIMEOUT: initialize Ethernet MAC failed because of timeout

      - ESP_FAIL: initialize Ethernet MAC failed because some other error occurred

  esp_err_t (*deinit)(esp_eth_mac_t *mac)

    Deinitialize Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Return:

      - ESP_OK: deinitialize Ethernet MAC successfully

      - ESP_FAIL: deinitialize Ethernet MAC failed because some error occurred

  esp_err_t (*start)(esp_eth_mac_t *mac)

    Start Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Return:

      - ESP_OK: start Ethernet MAC successfully

      - ESP_FAIL: start Ethernet MAC failed because some other error occurred

  esp_err_t (*stop)(esp_eth_mac_t *mac)

    Stop Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Return:

      - ESP_OK: stop Ethernet MAC successfully

      - ESP_FAIL: stop Ethernet MAC failed because some error occurred

  esp_err_t (*transmit)(esp_eth_mac_t *mac, uint8_t *buf, uint32_t length)

    Transmit packet from Ethernet MAC.

    Note

    Returned error codes may differ for each specific MAC chip.

    Param mac:

      [in] Ethernet MAC instance

    Param buf:

      [in] packet buffer to transmit

    Param length:

      [in] length of packet

    Return:

      - ESP_OK: transmit packet successfully

      - ESP_ERR_INVALID_SIZE: number of actually sent bytes differs to expected

      - ESP_FAIL: transmit packet failed because some other error occurred

  esp_err_t (*transmit_ctrl_vargs)(esp_eth_mac_t *mac, void *ctrl, uint32_t argc, va_list args)

    Transmit packet with extended control from Ethernet MAC and constructed with special parameters at Layer2.

    Note

    Typical intended use case is to make possible to construct a frame from multiple higher layer buffers without a need of buffer reallocations. However, other use cases are not limited.

    Note

    Returned error codes may differ for each specific MAC chip.

    Param mac:

      [in] Ethernet MAC instance

    Param ctrl:

      [in] optional transmit control structure (chip specific), set to NULL when not required

    Param argc:

      [in] number variable arguments

    Param args:

      [in] variable arguments

    Return:

      - ESP_OK: transmit packet successfully

      - ESP_ERR_INVALID_SIZE: number of actually sent bytes differs to expected

      - ESP_FAIL: transmit packet failed because some other error occurred

  esp_err_t (*transmit_vargs)(esp_eth_mac_t *mac, uint32_t argc, va_list args)

    Transmit packet from Ethernet MAC constructed with special parameters at Layer2.

    Note

    Typical intended use case is to make possible to construct a frame from multiple higher layer buffers without a need of buffer reallocations. However, other use cases are not limited.

    Note

    Returned error codes may differ for each specific MAC chip.

    Warning

    Deprecated, use `transmit_ctrl_vargs()` function instead.

    Param mac:

      [in] Ethernet MAC instance

    Param argc:

      [in] number variable arguments

    Param args:

      [in] variable arguments

    Return:

      - ESP_OK: transmit packet successfully

      - ESP_ERR_INVALID_SIZE: number of actually sent bytes differs to expected

      - ESP_FAIL: transmit packet failed because some other error occurred

  esp_err_t (*receive)(esp_eth_mac_t *mac, uint8_t *buf, uint32_t *length)

    Receive packet from Ethernet MAC.

    Note

    Memory of buf is allocated in the Layer2, make sure it get free after process.

    Note

    Before this function got invoked, the value of "length" should set by user, equals the size of buffer. After the function returned, the value of "length" means the real length of received data.

    Param mac:

      [in] Ethernet MAC instance

    Param buf:

      [out] packet buffer which will preserve the received frame

    Param length:

      [out] length of the received packet

    Return:

      - ESP_OK: receive packet successfully

      - ESP_ERR_INVALID_ARG: receive packet failed because of invalid argument

      - ESP_ERR_INVALID_SIZE: input buffer size is not enough to hold the incoming data. in this case, value of returned "length" indicates the real size of incoming data.

      - ESP_FAIL: receive packet failed because some other error occurred

  esp_err_t (*read_phy_reg)(esp_eth_mac_t *mac, uint32_t phy_addr, uint32_t phy_reg, uint32_t *reg_value)

    Read PHY register.

    Param mac:

      [in] Ethernet MAC instance

    Param phy_addr:

      [in] PHY chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [out] PHY register value

    Return:

      - ESP_OK: read PHY register successfully

      - ESP_ERR_INVALID_ARG: read PHY register failed because of invalid argument

      - ESP_ERR_INVALID_STATE: read PHY register failed because of wrong state of MAC

      - ESP_ERR_TIMEOUT: read PHY register failed because of timeout

      - ESP_FAIL: read PHY register failed because some other error occurred

  esp_err_t (*write_phy_reg)(esp_eth_mac_t *mac, uint32_t phy_addr, uint32_t phy_reg, uint32_t reg_value)

    Write PHY register.

    Param mac:

      [in] Ethernet MAC instance

    Param phy_addr:

      [in] PHY chip address (0~31)

    Param phy_reg:

      [in] PHY register index code

    Param reg_value:

      [in] PHY register value

    Return:

      - ESP_OK: write PHY register successfully

      - ESP_ERR_INVALID_STATE: write PHY register failed because of wrong state of MAC

      - ESP_ERR_TIMEOUT: write PHY register failed because of timeout

      - ESP_FAIL: write PHY register failed because some other error occurred

  esp_err_t (*set_addr)(esp_eth_mac_t *mac, uint8_t *addr)

    Set MAC address.

    Param mac:

      [in] Ethernet MAC instance

    Param addr:

      [in] MAC address

    Return:

      - ESP_OK: set MAC address successfully

      - ESP_ERR_INVALID_ARG: set MAC address failed because of invalid argument

      - ESP_FAIL: set MAC address failed because some other error occurred

  esp_err_t (*get_addr)(esp_eth_mac_t *mac, uint8_t *addr)

    Get MAC address.

    Param mac:

      [in] Ethernet MAC instance

    Param addr:

      [out] MAC address

    Return:

      - ESP_OK: get MAC address successfully

      - ESP_ERR_INVALID_ARG: get MAC address failed because of invalid argument

      - ESP_FAIL: get MAC address failed because some other error occurred

  esp_err_t (*add_mac_filter)(esp_eth_mac_t *mac, uint8_t *addr)

    Add Destination address MAC filter.

    Param mac:

      [in] Ethernet MAC instance

    Param addr:

      [in] MAC address

    Return:

      - ESP_OK: add MAC filter successfully

      - ESP_FAIL: add MAC filter failed because some error occurred

  esp_err_t (*rm_mac_filter)(esp_eth_mac_t *mac, uint8_t *addr)

    Remove Destination address MAC filter.

    Param mac:

      [in] Ethernet MAC instance

    Param addr:

      [in] MAC address

    Return:

      - ESP_OK: remove MAC filter successfully

      - ESP_FAIL: remove MAC filter failed because some error occurred

  esp_err_t (*set_speed)(esp_eth_mac_t *mac, eth_speed_t speed)

    Set speed of MAC.

    Param ma:c:

      [in] Ethernet MAC instance

    Param speed:

      [in] MAC speed

    Return:

      - ESP_OK: set MAC speed successfully

      - ESP_ERR_INVALID_ARG: set MAC speed failed because of invalid argument

      - ESP_FAIL: set MAC speed failed because some other error occurred

  esp_err_t (*set_duplex)(esp_eth_mac_t *mac, eth_duplex_t duplex)

    Set duplex mode of MAC.

    Param mac:

      [in] Ethernet MAC instance

    Param duplex:

      [in] MAC duplex

    Return:

      - ESP_OK: set MAC duplex mode successfully

      - ESP_ERR_INVALID_ARG: set MAC duplex failed because of invalid argument

      - ESP_FAIL: set MAC duplex failed because some other error occurred

  esp_err_t (*set_link)(esp_eth_mac_t *mac, eth_link_t link)

    Set link status of MAC.

    Param mac:

      [in] Ethernet MAC instance

    Param link:

      [in] Link status

    Return:

      - ESP_OK: set link status successfully

      - ESP_ERR_INVALID_ARG: set link status failed because of invalid argument

      - ESP_FAIL: set link status failed because some other error occurred

  esp_err_t (*set_promiscuous)(esp_eth_mac_t *mac, bool enable)

    Set promiscuous of MAC.

    Param mac:

      [in] Ethernet MAC instance

    Param enable:

      [in] set true to enable promiscuous mode; set false to disable promiscuous mode

    Return:

      - ESP_OK: set promiscuous mode successfully

      - ESP_FAIL: set promiscuous mode failed because some error occurred

  esp_err_t (*set_all_multicast)(esp_eth_mac_t *mac, bool enable)

    Set receive all multicast.

    Param mac:

      [in] Ethernet MAC instance

    Param enable:

      [in] set true to enable receive all multicast; set false to disable receive all multicast

    Return:

      - ESP_OK: set receive all multicast successfully

      - ESP_FAIL: set receive all multicast failed because some error occurred

  esp_err_t (*enable_flow_ctrl)(esp_eth_mac_t *mac, bool enable)

    Enable flow control on MAC layer or not.

    Param mac:

      [in] Ethernet MAC instance

    Param enable:

      [in] set true to enable flow control; set false to disable flow control

    Return:

      - ESP_OK: set flow control successfully

      - ESP_FAIL: set flow control failed because some error occurred

  esp_err_t (*set_peer_pause_ability)(esp_eth_mac_t *mac, uint32_t ability)

    Set the PAUSE ability of peer node.

    Param mac:

      [in] Ethernet MAC instance

    Param ability:

      [in] zero indicates that pause function is supported by link partner; non-zero indicates that pause function is not supported by link partner

    Return:

      - ESP_OK: set peer pause ability successfully

      - ESP_FAIL: set peer pause ability failed because some error occurred

  esp_err_t (*custom_ioctl)(esp_eth_mac_t *mac, int cmd, void *data)

    Custom IO function of MAC driver. This function is intended to extend common options of esp_eth_ioctl to cover specifics of MAC chip.

    Note

    This function may not be assigned when the MAC chip supports only most common set of configuration options.

    Param mac:

      [in] Ethernet MAC instance

    Param cmd:

      [in] IO control command

    Param data:

      [inout] address of data for `set` command or address where to store the data when used with `get` command

    Return:

      - ESP_OK: process io command successfully

      - ESP_ERR_INVALID_ARG: process io command failed because of some invalid argument

      - ESP_FAIL: process io command failed because some other error occurred

      - ESP_ERR_NOT_SUPPORTED: requested feature is not supported

  esp_err_t (*del)(esp_eth_mac_t *mac)

    Free memory of Ethernet MAC.

    Param mac:

      [in] Ethernet MAC instance

    Return:

      - ESP_OK: free Ethernet MAC instance successfully

      - ESP_FAIL: free Ethernet MAC instance failed because some error occurred

struct eth_mac_time_t

  Ethernet MAC Time Stamp.

  Public Members

  uint32_t seconds

    Seconds

  uint32_t nanoseconds

    Nanoseconds

struct eth_mac_config_t

  Configuration of Ethernet MAC object.

  Public Members

  uint32_t sw_reset_timeout_ms

    Software reset timeout value (Unit: ms)

  uint32_t rx_task_stack_size

    Stack size of the receive task

  uint32_t rx_task_prio

    Priority of the receive task

  uint32_t flags

    Flags that specify extra capability for mac driver

### Macros

ETH_MAC_FLAG_WORK_WITH_CACHE_DISABLE

  MAC driver can work when cache is disabled

ETH_MAC_FLAG_PIN_TO_CORE

  Pin MAC task to the CPU core where driver installation happened

ETH_MAC_DEFAULT_CONFIG()

  Default configuration for Ethernet MAC object.

### Type Definitions

typedef struct esp_eth_mac_s esp_eth_mac_t

  Ethernet MAC.

### Header File

- components/esp_eth/include/esp_eth_mac_esp.h

- This header file can be included with:

  >     #include "esp_eth_mac_esp.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Functions

esp_eth_mac_t *esp_eth_mac_new_esp32(const eth_esp32_emac_config_t *esp32_config, const eth_mac_config_t *config)

  Create ESP32 Ethernet MAC instance.

  Parameters:

    - esp32_config -- EMAC specific configuration

    - config -- Ethernet MAC configuration

  Returns:

    - instance: create MAC instance successfully

    - NULL: create MAC instance failed because some error occurred

### Unions

union eth_mac_clock_config_t
  #include <esp_eth_mac_esp.h>

  Ethernet MAC Clock Configuration.

  Public Members

  struct eth_mac_clock_config_t mii

    EMAC MII Clock Configuration

  emac_rmii_clock_mode_t clock_mode

    RMII Clock Mode Configuration

  int clock_gpio

    RMII Clock GPIO Configuration

  struct eth_mac_clock_config_t rmii

    EMAC RMII Clock Configuration

  int clock_rx_gpio

    RGMII Rx Clock GPIO Configuration

  int clock_tx_gpio

    RGMII Tx Clock GPIO Configuration

  int clock_phy_ref_gpio

    RGMII PHY_REF_CLK Clock GPIO Configuration

  struct eth_mac_clock_config_t rgmii

    EMAC RGMII Clock Configuration

### Structures

struct emac_esp_smi_gpio_config_t

  EMAC SMI GPIO configuration.

  Public Members

  int mdc_num

    SMI MDC GPIO number, set to -1 could bypass the SMI GPIO configuration

  int mdio_num

    SMI MDIO GPIO number, set to -1 could bypass the SMI GPIO configuration

struct eth_mac_mii_gpio_config_t

  EMAC MII data interface GPIO configuration.

  Public Members

  int tx_clk_num

    TX_CLK GPIO number

  int tx_en_num

    TX_EN GPIO number

  int txd0_num

    TXD0 GPIO number

  int txd1_num

    TXD1 GPIO number

  int txd2_num

    TXD2 GPIO number

  int txd3_num

    TXD3 GPIO number

  int rx_clk_num

    RX_CLK GPIO number

  int rx_dv_num

    RX_DV GPIO number

  int rxd0_num

    RXD0 GPIO number

  int rxd1_num

    RXD1 GPIO number

  int rxd2_num

    RXD2 GPIO number

  int rxd3_num

    RXD3 GPIO number

  int col_in_num

    COL_IN GPIO number

  int crs_in_num

    CRS_IN GPIO number

  int tx_er_num

    TX_ER GPIO number

  int rx_er_num

    RX_ER GPIO number

struct eth_mac_rmii_gpio_config_t

  EMAC RMII data interface GPIO configuration.

  Public Members

  int tx_en_num

    TX_EN GPIO number

  int txd0_num

    TXD0 GPIO number

  int txd1_num

    TXD1 GPIO number

  int crs_dv_num

    CRS_DV GPIO number

  int rxd0_num

    RXD0 GPIO number

  int rxd1_num

    RXD1 GPIO number

struct eth_mac_rgmii_gpio_config_t

  Ethernet MAC RGMII data interface GPIO configuration.

  Public Members

  int tx_ctl_num

    TX_CTL GPIO number

  int txd0_num

    TXD0 GPIO number

  int txd1_num

    TXD1 GPIO number

  int txd2_num

    TXD2 GPIO number

  int txd3_num

    TXD3 GPIO number

  int rx_ctl_num

    RX_CTL GPIO number

  int rxd0_num

    RXD0 GPIO number

  int rxd1_num

    RXD1 GPIO number

  int rxd2_num

    RXD2 GPIO number

  int rxd3_num

    RXD3 GPIO number

struct eth_esp32_emac_config_t

  EMAC specific configuration.

  Public Members

  emac_esp_smi_gpio_config_t smi_gpio

    SMI GPIO numbers

  eth_data_interface_t interface

    EMAC Data interface to PHY (MII/RMII)

  eth_mac_clock_config_t clock_config

    EMAC Interface clock configuration

  eth_mac_dma_burst_len_t dma_burst_len

    EMAC DMA burst length for both Tx and Rx

  int intr_priority

    EMAC interrupt priority, if set to 0 or a negative value, the driver will try to allocate an interrupt with a default priority

  int32_t mdc_freq_hz

    EMAC MDC frequency range limit, if set to 0 or a negative value, the driver will set the CSR clock range up to 2.5 MHz

### Macros

ETH_ESP32_EMAC_DEFAULT_CONFIG()

  Default ESP32's EMAC specific configuration.

### Enumerations

enum emac_rmii_clock_mode_t

  RMII Clock Mode Options.

  Values:

  enumerator EMAC_CLK_EXT_IN

    Input RMII Clock from external. EMAC Clock GPIO number needs to be configured when this option is selected.

    Note

    See components/esp_hal_emac/esp32(*)/emac_periph.c for available GPIO numbers.

  enumerator EMAC_CLK_OUT

    Output RMII Clock from internal PLL Clock. EMAC Clock GPIO number needs to be configured when this option is selected.

    Note

    See components/esp_hal_emac/esp32(*)/emac_periph.c for available GPIO numbers.

    Warning

    ESP32 Errata: If you want the Ethernet to work with Wi-Fi or BT, don’t select ESP32 as RMII CLK output as it would result in clock instability. Applicable only to ESP32, other ESP32 SoCs are not affected.

enum eth_mac_esp_io_cmd_t

  List of ESP EMAC specific commands for ioctl API.

  Values:

  enumerator ETH_MAC_ESP_CMD_SET_TDES0_CFG_BITS

    Set Transmit Descriptor Word 0 control bit mask (debug option)

  enumerator ETH_MAC_ESP_CMD_CLEAR_TDES0_CFG_BITS

    Clear Transmit Descriptor Word 0 control bit mask (debug option)

  enumerator ETH_MAC_ESP_CMD_DUMP_REGS

    Dump EMAC registers (debug option)

### Header File

- components/esp_eth/include/esp_eth_mac_spi.h

- This header file can be included with:

  >     #include "esp_eth_mac_spi.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Structures

struct eth_spi_custom_driver_config_t

  Custom SPI Driver Configuration. This structure declares configuration and callback functions to access Ethernet SPI module via user's custom SPI driver.

  Public Members

  void *config

    Custom driver specific configuration data used by `init()` function.

    Note

    Type and its content is fully under user's control

  void *(*init)(const void *spi_config)

    Custom driver SPI Initialization.

    Note

    return type and its content is fully under user's control

    Param spi_config:

      [in] Custom driver specific configuration

    Return:

      - spi_ctx: when initialization is successful, a pointer to context structure holding all variables needed for subsequent SPI access operations (e.g. SPI bus identification, mutexes, etc.)

      - NULL: driver initialization failed

  esp_err_t (*deinit)(void *spi_ctx)

    Custom driver De-initialization.

    Param spi_ctx:

      [in] a pointer to driver specific context structure

    Return:

      - ESP_OK: driver de-initialization was successful

      - ESP_FAIL: driver de-initialization failed

      - any other failure codes are allowed to be used to provide failure isolation

  esp_err_t (*read)(void *spi_ctx, uint32_t cmd, uint32_t addr, void *data, uint32_t data_len)

    Custom driver SPI read.

    Note

    The read function is responsible to construct command, address and data fields of the SPI frame in format expected by particular SPI Ethernet module

    Param spi_ctx:

      [in] a pointer to driver specific context structure

    Param cmd:

      [in] command

    Param addr:

      [in] register address

    Param data:

      [out] read data

    Param data_len:

      [in] read data length in bytes

    Return:

      - ESP_OK: read was successful

      - ESP_FAIL: read failed

      - any other failure codes are allowed to be used to provide failure isolation

  esp_err_t (*write)(void *spi_ctx, uint32_t cmd, uint32_t addr, const void *data, uint32_t data_len)

    Custom driver SPI write.

    Note

    The write function is responsible to construct command, address and data fields of the SPI frame in format expected by particular SPI Ethernet module

    Param spi_ctx:

      [in] a pointer to driver specific context structure

    Param cmd:

      [in] command

    Param addr:

      [in] register address

    Param data:

      [in] data to write

    Param data_len:

      [in] length of data to write in bytes

    Return:

      - ESP_OK: write was successful

      - ESP_FAIL: write failed

      - any other failure codes are allowed to be used to provide failure isolation

### Macros

ETH_DEFAULT_SPI

  Default configuration of the custom SPI driver. Internal ESP-IDF SPI Master driver is used by default.

### Header File

- components/esp_eth/include/esp_eth_phy.h

- This header file can be included with:

  >     #include "esp_eth_phy.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Functions

esp_eth_phy_t *esp_eth_phy_new_generic(const eth_phy_config_t *config)

  Create a PHY instance of generic chip which conforms with IEEE 802.3.

  Note

  Default reset timing configuration is set conservatively(see internals of the function). If you need faster response and your chip supports it, configure it via `config` parameter.

  Warning

  While basic functionality should always work, some specific features might be limited, even if the PHY meets IEEE 802.3 standard. A typical example is loopback functionality, where certain PHYs may require setting a specific speed mode to operate correctly.

  Parameters:

    config -- [in] configuration of PHY

  Returns:

    - instance: create PHY instance successfully

    - NULL: create PHY instance failed because some error occurred

### Structures

struct esp_eth_phy_s

  Ethernet PHY.

  Public Members

  esp_err_t (*set_mediator)(esp_eth_phy_t *phy, esp_eth_mediator_t *mediator)

    Set mediator for PHY.

    Param phy:

      [in] Ethernet PHY instance

    Param mediator:

      [in] mediator of Ethernet driver

    Return:

      - ESP_OK: set mediator for Ethernet PHY instance successfully

      - ESP_ERR_INVALID_ARG: set mediator for Ethernet PHY instance failed because of some invalid arguments

  esp_err_t (*reset)(esp_eth_phy_t *phy)

    Software Reset Ethernet PHY.

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: reset Ethernet PHY successfully

      - ESP_FAIL: reset Ethernet PHY failed because some error occurred

  esp_err_t (*reset_hw)(esp_eth_phy_t *phy)

    Hardware Reset Ethernet PHY.

    Note

    Hardware reset is mostly done by pull down and up PHY's nRST pin

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: reset Ethernet PHY successfully

      - ESP_FAIL: reset Ethernet PHY failed because some error occurred

  esp_err_t (*init)(esp_eth_phy_t *phy)

    Initialize Ethernet PHY.

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: initialize Ethernet PHY successfully

      - ESP_FAIL: initialize Ethernet PHY failed because some error occurred

  esp_err_t (*deinit)(esp_eth_phy_t *phy)

    Deinitialize Ethernet PHY.

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: deinitialize Ethernet PHY successfully

      - ESP_FAIL: deinitialize Ethernet PHY failed because some error occurred

  esp_err_t (*autonego_ctrl)(esp_eth_phy_t *phy, eth_phy_autoneg_cmd_t cmd, bool *autonego_en_stat)

    Configure auto negotiation.

    Param phy:

      [in] Ethernet PHY instance

    Param cmd:

      [in] Configuration command, it is possible to Enable (restart), Disable or get current status of PHY auto negotiation

    Param autonego_en_stat:

      [out] Address where to store current status of auto negotiation configuration

    Return:

      - ESP_OK: restart auto negotiation successfully

      - ESP_FAIL: restart auto negotiation failed because some error occurred

      - ESP_ERR_INVALID_ARG: invalid command

  esp_err_t (*get_link)(esp_eth_phy_t *phy)

    Get Ethernet PHY link status.

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: get Ethernet PHY link status successfully

      - ESP_FAIL: get Ethernet PHY link status failed because some error occurred

  esp_err_t (*set_link)(esp_eth_phy_t *phy, eth_link_t link)

    Set Ethernet PHY link status.

    Param phy:

      [in] Ethernet PHY instance

    Param link:

      [in] new link status

    Return:

      - ESP_OK: set Ethernet PHY link status successfully

      - ESP_FAIL: set Ethernet PHY link status failed because some error occurred

  esp_err_t (*pwrctl)(esp_eth_phy_t *phy, bool enable)

    Power control of Ethernet PHY.

    Param phy:

      [in] Ethernet PHY instance

    Param enable:

      [in] set true to power on Ethernet PHY; ser false to power off Ethernet PHY

    Return:

      - ESP_OK: control Ethernet PHY power successfully

      - ESP_FAIL: control Ethernet PHY power failed because some error occurred

  esp_err_t (*set_addr)(esp_eth_phy_t *phy, uint32_t addr)

    Set PHY chip address.

    Param phy:

      [in] Ethernet PHY instance

    Param addr:

      [in] PHY chip address

    Return:

      - ESP_OK: set Ethernet PHY address successfully

      - ESP_FAIL: set Ethernet PHY address failed because some error occurred

  esp_err_t (*get_addr)(esp_eth_phy_t *phy, uint32_t *addr)

    Get PHY chip address.

    Param phy:

      [in] Ethernet PHY instance

    Param addr:

      [out] PHY chip address

    Return:

      - ESP_OK: get Ethernet PHY address successfully

      - ESP_ERR_INVALID_ARG: get Ethernet PHY address failed because of invalid argument

  esp_err_t (*advertise_pause_ability)(esp_eth_phy_t *phy, uint32_t ability)

    Advertise pause function supported by MAC layer.

    Param phy:

      [in] Ethernet PHY instance

    Param addr:

      [out] Pause ability

    Return:

      - ESP_OK: Advertise pause ability successfully

      - ESP_ERR_INVALID_ARG: Advertise pause ability failed because of invalid argument

  esp_err_t (*loopback)(esp_eth_phy_t *phy, bool enable)

    Sets the PHY to loopback mode.

    Param phy:

      [in] Ethernet PHY instance

    Param enable:

      [in] enables or disables PHY loopback

    Return:

      - ESP_OK: PHY instance loopback mode has been configured successfully

      - ESP_FAIL: PHY instance loopback configuration failed because some error occurred

  esp_err_t (*set_speed)(esp_eth_phy_t *phy, eth_speed_t speed)

    Sets PHY speed mode.

    Note

    Autonegotiation feature needs to be disabled prior to calling this function for the new setting to be applied

    Param phy:

      [in] Ethernet PHY instance

    Param speed:

      [in] Speed mode to be set

    Return:

      - ESP_OK: PHY instance speed mode has been configured successfully

      - ESP_FAIL: PHY instance speed mode configuration failed because some error occurred

  esp_err_t (*set_duplex)(esp_eth_phy_t *phy, eth_duplex_t duplex)

    Sets PHY duplex mode.

    Note

    Autonegotiation feature needs to be disabled prior to calling this function for the new setting to be applied

    Param phy:

      [in] Ethernet PHY instance

    Param duplex:

      [in] Duplex mode to be set

    Return:

      - ESP_OK: PHY instance duplex mode has been configured successfully

      - ESP_FAIL: PHY instance duplex mode configuration failed because some error occurred

  esp_err_t (*custom_ioctl)(esp_eth_phy_t *phy, int cmd, void *data)

    Custom IO function of PHY driver. This function is intended to extend common options of esp_eth_ioctl to cover specifics of PHY chip.

    Note

    This function may not be assigned when the PHY chip supports only most common set of configuration options.

    Param phy:

      [in] Ethernet PHY instance

    Param cmd:

      [in] IO control command

    Param data:

      [inout] address of data for `set` command or address where to store the data when used with `get` command

    Return:

      - ESP_OK: process io command successfully

      - ESP_ERR_INVALID_ARG: process io command failed because of some invalid argument

      - ESP_FAIL: process io command failed because some other error occurred

      - ESP_ERR_NOT_SUPPORTED: requested feature is not supported

  esp_err_t (*del)(esp_eth_phy_t *phy)

    Free memory of Ethernet PHY instance.

    Param phy:

      [in] Ethernet PHY instance

    Return:

      - ESP_OK: free PHY instance successfully

      - ESP_FAIL: free PHY instance failed because some error occurred

struct eth_phy_config_t

  Ethernet PHY configuration.

  Public Members

  int32_t phy_addr

    PHY address, set -1 to enable PHY address detection at initialization stage

  uint32_t reset_timeout_ms

    Reset timeout value (Unit: ms)

  uint32_t autonego_timeout_ms

    Auto-negotiation timeout value (Unit: ms)

  int reset_gpio_num

    Reset GPIO number, -1 means no hardware reset

  int32_t hw_reset_assert_time_us

    Time the reset pin is asserted (Unit: us), 0 to use chip specific default

  int32_t post_hw_reset_delay_ms

    Time to wait after the HW reset (Unit: ms), 0 to use chip specific default, -1 means no wait

### Macros

ESP_ETH_PHY_ADDR_AUTO

ESP_ETH_NO_POST_HW_RESET_DELAY

ETH_PHY_DEFAULT_CONFIG()

  Default configuration for Ethernet PHY object.

### Type Definitions

typedef struct esp_eth_phy_s esp_eth_phy_t

  Ethernet PHY.

### Enumerations

enum eth_phy_autoneg_cmd_t

  Auto-negotiation control commands.

  Values:

  enumerator ESP_ETH_PHY_AUTONEGO_RESTART
  enumerator ESP_ETH_PHY_AUTONEGO_EN
  enumerator ESP_ETH_PHY_AUTONEGO_DIS
  enumerator ESP_ETH_PHY_AUTONEGO_G_STAT

### Header File

- components/esp_eth/include/esp_eth_phy_802_3.h

- This header file can be included with:

  >     #include "esp_eth_phy_802_3.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Functions

esp_err_t esp_eth_phy_802_3_set_mediator(phy_802_3_t *phy_802_3, esp_eth_mediator_t *eth)

  Set Ethernet mediator.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - eth -- Ethernet mediator pointer

  Returns:

    - ESP_OK: Ethermet mediator set successfully

    - ESP_ERR_INVALID_ARG: if `eth` is `NULL`

esp_err_t esp_eth_phy_802_3_reset(phy_802_3_t *phy_802_3)

  Reset PHY.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: Ethernet PHY reset successfully

    - ESP_FAIL: reset Ethernet PHY failed because some error occurred

esp_err_t esp_eth_phy_802_3_autonego_ctrl(phy_802_3_t *phy_802_3, eth_phy_autoneg_cmd_t cmd, bool *autonego_en_stat)

  Control autonegotiation mode of Ethernet PHY.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - cmd -- autonegotiation command enumeration

    - autonego_en_stat -- [out] autonegotiation enabled flag

  Returns:

    - ESP_OK: Ethernet PHY autonegotiation configured successfully

    - ESP_FAIL: Ethernet PHY autonegotiation configuration fail because some error occurred

    - ESP_ERR_INVALID_ARG: invalid value of `cmd`

esp_err_t esp_eth_phy_802_3_updt_link_dup_spd(phy_802_3_t *phy_802_3)

  Retrieve link status and propagate the status to higher layers if the status changed.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: Ethernet PHY link status retrieved successfully

    - ESP_FAIL: Error occurred during reading registry

esp_err_t esp_eth_phy_802_3_pwrctl(phy_802_3_t *phy_802_3, bool enable)

  Power control of Ethernet PHY.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - enable -- set true to power ON Ethernet PHY; set false to power OFF Ethernet PHY

  Returns:

    - ESP_OK: Ethernet PHY power down mode set successfully

    - ESP_FAIL: Ethernet PHY power up or power down failed because some error occurred

esp_err_t esp_eth_phy_802_3_set_addr(phy_802_3_t *phy_802_3, uint32_t addr)

  Set Ethernet PHY address.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - addr -- new PHY address

  Returns:

    - ESP_OK: Ethernet PHY address set

esp_err_t esp_eth_phy_802_3_get_addr(phy_802_3_t *phy_802_3, uint32_t *addr)

  Get Ethernet PHY address.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - addr -- [out] Ethernet PHY address

  Returns:

    - ESP_OK: Ethernet PHY address read successfully

    - ESP_ERR_INVALID_ARG: `addr` pointer is `NULL`

esp_err_t esp_eth_phy_802_3_advertise_pause_ability(phy_802_3_t *phy_802_3, uint32_t ability)

  Advertise pause function ability.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - ability -- enable or disable pause ability

  Returns:

    - ESP_OK: pause ability set successfully

    - ESP_FAIL: Advertise pause function ability failed because some error occurred

esp_err_t esp_eth_phy_802_3_loopback(phy_802_3_t *phy_802_3, bool enable)

  Set Ethernet PHY loopback mode.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - enable -- set true to enable loopback; set false to disable loopback

  Returns:

    - ESP_OK: Ethernet PHY loopback mode set successfully

    - ESP_FAIL: Ethernet PHY loopback configuration failed because some error occurred

esp_err_t esp_eth_phy_802_3_set_speed(phy_802_3_t *phy_802_3, eth_speed_t speed)

  Set Ethernet PHY speed.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - speed -- new speed of Ethernet PHY link

  Returns:

    - ESP_OK: Ethernet PHY speed set successfully

    - ESP_FAIL: Set Ethernet PHY speed failed because some error occurred

esp_err_t esp_eth_phy_802_3_set_duplex(phy_802_3_t *phy_802_3, eth_duplex_t duplex)

  Set Ethernet PHY duplex mode.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - duplex -- new duplex mode for Ethernet PHY link

  Returns:

    - ESP_OK: Ethernet PHY duplex mode set successfully

    - ESP_ERR_INVALID_STATE: unable to set duplex mode to Half if loopback is enabled

    - ESP_FAIL: Set Ethernet PHY duplex mode failed because some error occurred

esp_err_t esp_eth_phy_802_3_set_link(phy_802_3_t *phy_802_3, eth_link_t link)

  Set Ethernet PHY link status.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - link -- new link status

  Returns:

    - ESP_OK: Ethernet PHY link set successfully

esp_err_t esp_eth_phy_802_3_init(phy_802_3_t *phy_802_3)

  Initialize Ethernet PHY.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: Ethernet PHY initialized successfully

esp_err_t esp_eth_phy_802_3_deinit(phy_802_3_t *phy_802_3)

  Power off Eternet PHY.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: Ethernet PHY powered off successfully

esp_err_t esp_eth_phy_802_3_del(phy_802_3_t *phy_802_3)

  Delete Ethernet PHY infostructure.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: Ethernet PHY infostructure deleted

esp_err_t esp_eth_phy_802_3_reset_hw(phy_802_3_t *phy_802_3)

  Performs hardware reset with internal timing configuration defined during initialization.

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: reset Ethernet PHY successfully

    - ESP_ERR_NOT_ALLOWED: reset GPIO not defined

esp_err_t esp_eth_phy_802_3_detect_phy_addr(esp_eth_mediator_t *eth, int *detected_addr)

  Detect PHY address.

  Parameters:

    - eth -- Mediator of Ethernet driver

    - detected_addr -- [out] a valid address after detection

  Returns:

    - ESP_OK: detect phy address successfully

    - ESP_ERR_INVALID_ARG: invalid parameter

    - ESP_ERR_NOT_FOUND: can't detect any PHY device

    - ESP_FAIL: detect phy address failed because some error occurred

esp_err_t esp_eth_phy_802_3_basic_phy_init(phy_802_3_t *phy_802_3)

  Performs basic PHY chip initialization.

  Note

  It should be called as the first function in PHY specific driver instance

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: initialized Ethernet PHY successfully

    - ESP_FAIL: initialization of Ethernet PHY failed because some error occurred

    - ESP_ERR_INVALID_ARG: invalid argument

    - ESP_ERR_NOT_FOUND: PHY device not detected

    - ESP_ERR_TIMEOUT: MII Management read/write operation timeout

    - ESP_ERR_INVALID_STATE: PHY is in invalid state to perform requested operation

esp_err_t esp_eth_phy_802_3_basic_phy_deinit(phy_802_3_t *phy_802_3)

  Performs basic PHY chip de-initialization.

  Note

  It should be called as the last function in PHY specific driver instance

  Parameters:

    phy_802_3 -- IEEE 802.3 PHY object infostructure

  Returns:

    - ESP_OK: de-initialized Ethernet PHY successfully

    - ESP_FAIL: de-initialization of Ethernet PHY failed because some error occurred

    - ESP_ERR_TIMEOUT: MII Management read/write operation timeout

    - ESP_ERR_INVALID_STATE: PHY is in invalid state to perform requested operation

esp_err_t esp_eth_phy_802_3_read_oui(phy_802_3_t *phy_802_3, uint32_t *oui)

  Reads raw content of OUI field.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - oui -- [out] OUI value

  Returns:

    - ESP_OK: OUI field read successfully

    - ESP_FAIL: OUI field read failed because some error occurred

    - ESP_ERR_INVALID_ARG: invalid `oui` argument

    - ESP_ERR_TIMEOUT: MII Management read/write operation timeout

    - ESP_ERR_INVALID_STATE: PHY is in invalid state to perform requested operation

esp_err_t esp_eth_phy_802_3_read_manufac_info(phy_802_3_t *phy_802_3, uint8_t *model, uint8_t *rev)

  Reads manufacturer’s model and revision number.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - model -- [out] Manufacturer’s model number (can be NULL when not required)

    - rev -- [out] Manufacturer’s revision number (can be NULL when not required)

  Returns:

    - ESP_OK: Manufacturer’s info read successfully

    - ESP_FAIL: Manufacturer’s info read failed because some error occurred

    - ESP_ERR_TIMEOUT: MII Management read/write operation timeout

    - ESP_ERR_INVALID_STATE: PHY is in invalid state to perform requested operation

esp_err_t esp_eth_phy_802_3_get_mmd_addr(phy_802_3_t *phy_802_3, uint8_t devaddr, uint16_t *mmd_addr)

  Reads MDIO device's internal address register.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - mmd_addr -- [out] Current address stored in device's register

  Returns:

    - ESP_OK: Address register read successfully

    - ESP_FAIL: Address register read failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits)

esp_err_t esp_eth_phy_802_3_set_mmd_addr(phy_802_3_t *phy_802_3, uint8_t devaddr, uint16_t mmd_addr)

  Write to DIO device's internal address register.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - mmd_addr -- [out] New value of MDIO device's address register value

  Returns:

    - ESP_OK: Address register written to successfully

    - ESP_FAIL: Address register write failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits)

esp_err_t esp_eth_phy_802_3_read_mmd_data(phy_802_3_t *phy_802_3, uint8_t devaddr, esp_eth_phy_802_3_mmd_func_t function, uint32_t *data)

  Read data of MDIO device's memory at address register.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - function -- MMD function

    - data -- [out] Data read from the device's memory

  Returns:

    - ESP_OK: Memory read successfully

    - ESP_FAIL: Memory read failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits) or MMD access function is invalid

esp_err_t esp_eth_phy_802_3_write_mmd_data(phy_802_3_t *phy_802_3, uint8_t devaddr, esp_eth_phy_802_3_mmd_func_t function, uint32_t data)

  Write data to MDIO device's memory at address register.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - function -- MMD function

    - data -- [out] Data to write to the device's memory

  Returns:

    - ESP_OK: Memory written successfully

    - ESP_FAIL: Memory write failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits) or MMD access function is invalid

esp_err_t esp_eth_phy_802_3_read_mmd_register(phy_802_3_t *phy_802_3, uint8_t devaddr, uint16_t mmd_addr, uint32_t *data)

  Set MMD address to mmd_addr with function MMD_FUNC_NOINCR and read contents to *data.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - mmd_addr -- Address of MDIO device register

    - data -- [out] Data read from the device's memory

  Returns:

    - ESP_OK: Memory read successfully

    - ESP_FAIL: Memory read failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits)

esp_err_t esp_eth_phy_802_3_write_mmd_register(phy_802_3_t *phy_802_3, uint8_t devaddr, uint16_t mmd_addr, uint32_t data)

  Set MMD address to mmd_addr with function MMD_FUNC_NOINCR and write data.

  Parameters:

    - phy_802_3 -- IEEE 802.3 PHY object infostructure

    - devaddr -- Address of MDIO device

    - mmd_addr -- Address of MDIO device register

    - data -- [out] Data to write to the device's memory

  Returns:

    - ESP_OK: Memory written to successfully

    - ESP_FAIL: Memory write failed because of some error occurred

    - ESP_ERR_INVALID_ARG: Device address provided is out of range (hardware limits device address to 5 bits)

inline phy_802_3_t *esp_eth_phy_into_phy_802_3(esp_eth_phy_t *phy)

  Returns address to parent IEEE 802.3 PHY object infostructure.

  Parameters:

    phy -- Ethernet PHY instance

  Returns:

    phy_802_3_t*

    - address to parent IEEE 802.3 PHY object infostructure

esp_err_t esp_eth_phy_802_3_obj_config_init(phy_802_3_t *phy_802_3, const eth_phy_config_t *config)

  Initializes configuration of parent IEEE 802.3 PHY object infostructure.

  Parameters:

    - phy_802_3 -- Address to IEEE 802.3 PHY object infostructure

    - config -- Configuration of the IEEE 802.3 PHY object

  Returns:

    - ESP_OK: configuration initialized successfully

    - ESP_ERR_INVALID_ARG: invalid `config` argument

### Structures

struct phy_802_3_t

  IEEE 802.3 PHY object infostructure.

  Public Members

  esp_eth_phy_t parent

    Parent Ethernet PHY instance

  esp_eth_mediator_t *eth

    Mediator of Ethernet driver

  int addr

    PHY address

  uint32_t reset_timeout_ms

    Reset timeout value (Unit: ms)

  uint32_t autonego_timeout_ms

    Auto-negotiation timeout value (Unit: ms)

  eth_link_t link_status

    Current Link status

  int reset_gpio_num

    Reset GPIO number, -1 means no hardware reset

  int32_t hw_reset_assert_time_us

    Time the reset pin is asserted (Unit: us)

  int32_t post_hw_reset_delay_ms

    Time to wait after the HW reset (Unit: ms)

### Enumerations

enum esp_eth_phy_802_3_mmd_func_t

  IEEE 802.3 MMD modes enumeration.

  Values:

  enumerator MMD_FUNC_ADDRESS
  enumerator MMD_FUNC_DATA_NOINCR
  enumerator MMD_FUNC_DATA_RWINCR
  enumerator MMD_FUNC_DATA_WINCR

### Header File

- components/esp_eth/include/esp_eth_netif_glue.h

- This header file can be included with:

  >     #include "esp_eth_netif_glue.h"

- This header file is a part of the API provided by the `esp_eth` component. To declare that your component depends on `esp_eth`, add the following to your CMakeLists.txt:

  >     REQUIRES esp_eth

  > or

  >     PRIV_REQUIRES esp_eth

### Functions

esp_eth_netif_glue_handle_t esp_eth_new_netif_glue(esp_eth_handle_t eth_hdl)

  Create a netif glue for Ethernet driver.

  Note

  netif glue is used to attach io driver to TCP/IP netif

  Parameters:

    eth_hdl -- Ethernet driver handle

  Returns:

    glue object, which inherits esp_netif_driver_base_t

esp_err_t esp_eth_del_netif_glue(esp_eth_netif_glue_handle_t eth_netif_glue)

  Delete netif glue of Ethernet driver.

  Parameters:

    eth_netif_glue -- netif glue

  Returns:

    -ESP_OK: delete netif glue successfully

### Type Definitions

typedef struct esp_eth_netif_glue_t *esp_eth_netif_glue_handle_t

  Handle of netif glue - an intermediate layer between netif and Ethernet driver.

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