Module efuse 

eFuse (one-time programmable configuration)

Overview

The efuse module provides functionality for reading eFuse data from the chip, allowing access to various chip-specific information such as:

• MAC address
• Chip revision

and more. It is useful for retrieving chip-specific configuration and identification data during runtime.

Examples

Reading interface MAC addresses

use esp_hal::efuse::{self, InterfaceMacAddress};

let mac = efuse::interface_mac_address(InterfaceMacAddress::Station);
println!("MAC: {mac}");
println!("MAC bytes: {:02x?}", mac.as_bytes());

Structs

ChipRevision

Represents the hardware revision.

EfuseFieldunstable

The bit field for get access to efuse data

MacAddress

Hardware (MAC) address.

Enums

ChipTypeunstable

Representing different types of ESP32 chips.

InterfaceMacAddress

Interface selection for interface_mac_address.

SetMacErrorunstable

Error indicating issues with setting the MAC address.

Constants

ABS_DONE_0unstable

Secure boot V1 is enabled for bootloader image

ABS_DONE_1unstable

Secure boot V2 is enabled for bootloader image

ADC1_TP_HIGHunstable

ADC1 Two Point calibration high point. Only valid if EFUSE_RD_BLK3_PART_RESERVE

ADC1_TP_LOWunstable

ADC1 Two Point calibration low point. Only valid if EFUSE_RD_BLK3_PART_RESERVE

ADC2_TP_HIGHunstable

ADC2 Two Point calibration high point. Only valid if EFUSE_RD_BLK3_PART_RESERVE

ADC2_TP_LOWunstable

ADC2 Two Point calibration low point. Only valid if EFUSE_RD_BLK3_PART_RESERVE

ADC_VREFunstable

True ADC reference voltage

BLK3_PART_RESERVEunstable

BLOCK3 partially served for ADC calibration data

BLK3_RESERVED_2unstable

read for BLOCK3

BLK3_RESERVED_6unstable

read for BLOCK3

BLK3_RESERVED_7unstable

read for BLOCK3

BLOCK1unstable

Flash encryption key

BLOCK2unstable

Security boot key

CHIP_CPU_FREQ_LOWunstable

If set alongside EFUSE_RD_CHIP_CPU_FREQ_RATED; the ESP32’s max CPU frequency is rated for 160MHz. 240MHz otherwise

CHIP_CPU_FREQ_RATEDunstable

If set; the ESP32’s maximum CPU frequency has been rated

CHIP_PACKAGEunstable

Chip package identifier

CHIP_PACKAGE_4BITunstable

Chip package identifier #4bit

CHIP_VER_REV1unstable

bit is set to 1 for rev1 silicon

CHIP_VER_REV2unstable

CLK8M_FREQunstable

8MHz clock freq override

CODING_SCHEMEunstable

Efuse variable block length scheme

CONSOLE_DEBUG_DISABLEunstable

Disable ROM BASIC interpreter fallback

CUSTOM_MACunstable

Custom MAC address

CUSTOM_MAC_CRCunstable

CRC8 for custom MAC address

DISABLE_APP_CPUunstable

Disables APP CPU

DISABLE_BTunstable

Disables Bluetooth

DISABLE_DL_CACHEunstable

Disable flash cache in UART bootloader

DISABLE_DL_DECRYPTunstable

Disable flash decryption in UART bootloader

DISABLE_DL_ENCRYPTunstable

Disable flash encryption in UART bootloader

DISABLE_SDIO_HOSTunstable

DIS_CACHEunstable

Disables cache

FLASH_CRYPT_CNTunstable

Flash encryption is enabled if this field has an odd number of bits set

FLASH_CRYPT_CONFIGunstable

Flash encryption config (key tweak bits)

JTAG_DISABLEunstable

Disable JTAG

KEY_STATUSunstable

Usage of efuse block 3 (reserved)

MAC0unstable

MAC address

MAC1unstable

MAC address

MAC_CRCunstable

CRC8 for MAC address

MAC_VERSIONunstable

Version of the MAC field

RD_DISunstable

Disable reading from BlOCK1-3

RESERVED_0_28unstable

reserved

RESERVED_3_56unstable

reserved

RESERVED_3_160unstable

reserved

RESERVE_0_88unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_112unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_141unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_145unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_181unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_186unstable

Reserved; it was created by set_missed_fields_in_regs func

RESERVE_0_203unstable

Reserved; it was created by set_missed_fields_in_regs func

SECURE_VERSIONunstable

Secure version for anti-rollback

SPI_PAD_CONFIG_CLKunstable

Override SD_CLK pad (GPIO6/SPICLK)

SPI_PAD_CONFIG_CS0unstable

Override SD_CMD pad (GPIO11/SPICS0)

SPI_PAD_CONFIG_Dunstable

Override SD_DATA_1 pad (GPIO8/SPID)

SPI_PAD_CONFIG_HDunstable

read for SPI_pad_config_hd

SPI_PAD_CONFIG_Qunstable

Override SD_DATA_0 pad (GPIO7/SPIQ)

UART_DOWNLOAD_DISunstable

Disable UART download mode. Valid for ESP32 V3 and newer; only

VOL_LEVEL_HP_INVunstable

This field stores the voltage level for CPU to run at 240 MHz; or for flash/PSRAM to run at 80 MHz.0x0: level 7; 0x1: level 6; 0x2: level 5; 0x3: level 4. (RO)

WAFER_VERSION_MINORunstable

WR_DISunstable

Efuse write disable mask

XPD_SDIO_FORCEunstable

Ignore MTDI pin (GPIO12) for VDD_SDIO on reset

XPD_SDIO_REGunstable

read for XPD_SDIO_REG

XPD_SDIO_TIEHunstable

If XPD_SDIO_FORCE & XPD_SDIO_REG

Functions

base_mac_addressunstable

Returns the base MAC address programmed into eFuse during manufacturing.

chip_revision

Returns the hardware revision.

chip_typeunstable

Returns the CHIP_VER_PKG eFuse value.

core_countunstable

Returns the number of CPUs available on the chip.

flash_encryptionunstable

Get status of SPI boot encryption.

interface_mac_address

Returns the MAC address for a specific interface, derived from the base MAC.

is_bluetooth_enabledunstable

Returns the CHIP_VER_DIS_BT eFuse value.

major_chip_versionunstable

Returns the major hardware revision

max_cpu_frequencyunstable

Returns the maximum rated clock of the CPU in MHz.

minor_chip_versionunstable

Returns the minor hardware revision

override_mac_addressunstable

Overrides the base MAC address used by interface_mac_address.

read_bitunstable

Read bit value.

read_field_leunstable

Read field value in a little-endian order