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

AdcCalibUnitunstable

Selects which ADC we are interested in the efuse calibration data for

InterfaceMacAddress

Interface selection for interface_mac_address.

RtcCalibParamunstable

Parameter selected from the ESP32-S2 RTC calibration table

SetMacErrorunstable

Error indicating issues with setting the MAC address.

Constants

ADC_CALIBunstable

4 bit of ADC calibration

BLK_VERSION_MAJORunstable

BLK_VERSION_MAJOR

BLK_VERSION_MINORunstable

BLK_VERSION_MINOR of BLOCK2

BLOCK0_VERSIONunstable

BLOCK0 efuse version

BLOCK_KEY0unstable

Key0 or user data

BLOCK_KEY1unstable

Key1 or user data

BLOCK_KEY2unstable

Key2 or user data

BLOCK_KEY3unstable

Key3 or user data

BLOCK_KEY4unstable

Key4 or user data

BLOCK_KEY5unstable

Key5 or user data

BLOCK_SYS_DATA2unstable

System data part 2 (reserved)

BLOCK_USR_DATAunstable

User data

CUSTOM_MACunstable

Custom MAC

DISABLE_BLK_VERSION_MAJORunstable

Disables check of blk version major

DISABLE_WAFER_VERSION_MAJORunstable

Disables check of wafer version major

DIS_BOOT_REMAPunstable

Disables capability to Remap RAM to ROM address space

DIS_DCACHEunstable

Set this bit to disable Dcache

DIS_DOWNLOAD_DCACHEunstable

Disables Dcache when SoC is in Download mode

DIS_DOWNLOAD_ICACHEunstable

Disables Icache when SoC is in Download mode

DIS_DOWNLOAD_MANUAL_ENCRYPTunstable

Disables flash encryption when in download boot modes

DIS_DOWNLOAD_MODEunstable

Set this bit to disable all download boot modes

DIS_FORCE_DOWNLOADunstable

Set this bit to disable the function that forces chip into download mode

DIS_ICACHEunstable

Set this bit to disable Icache

DIS_LEGACY_SPI_BOOTunstable

Set this bit to disable Legacy SPI boot mode

DIS_RTC_RAM_BOOTunstable

Reserved

DIS_TWAIunstable

Set this bit to disable the TWAI Controller function

DIS_USBunstable

Set this bit to disable USB OTG function

DIS_USB_DOWNLOAD_MODEunstable

Set this bit to disable use of USB OTG in UART download boot mode

ENABLE_SECURITY_DOWNLOADunstable

Set this bit to enable secure UART download mode (read/write flash only)

FLASH_TPUWunstable

Configures flash startup delay after SoC power-up; in unit of (ms/2). When the value is 15; delay is 7.5 ms

FLASH_TYPEunstable

SPI flash type

FLASH_VERSIONunstable

Flash version

FORCE_SEND_RESUMEunstable

If set; forces ROM code to send an SPI flash resume command during SPI boot

HARD_DIS_JTAGunstable

Hardware disables JTAG permanently

KEY_PURPOSE_0unstable

Purpose of KEY0

KEY_PURPOSE_1unstable

Purpose of KEY1

KEY_PURPOSE_2unstable

Purpose of KEY2

KEY_PURPOSE_3unstable

Purpose of KEY3

KEY_PURPOSE_4unstable

Purpose of KEY4

KEY_PURPOSE_5unstable

Purpose of KEY5

KEY_PURPOSE_6unstable

Purpose of KEY6

MAC0unstable

MAC address

MAC1unstable

MAC address

OPTIONAL_UNIQUE_IDunstable

Optional unique 128-bit ID

PIN_POWER_SELECTIONunstable

Set default power supply for GPIO33-GPIO37; set when SPI flash is initialized

PKG_VERSIONunstable

Package version

PSRAM_VERSIONunstable

PSRAM version

RD_DISunstable

Disable reading from BlOCK4-10

RESERVED_0_162unstable

reserved

RESERVED_1_123unstable

reserved

RESERVED_1_135unstable

reserved

RESERVED_3_192unstable

reserved

RESERVED_3_248unstable

reserved

RPT4_RESERVED1unstable

Reserved (used for four backups method)

RPT4_RESERVED2unstable

Reserved (used for four backups method)

RPT4_RESERVED3unstable

Reserved (used for four backups method)

RPT4_RESERVED5unstable

Reserved (used for four backups method)

RTCCALIB_V1IDX_A10Hunstable

RTCCALIB_V1IDX_A10Lunstable

RTCCALIB_V1IDX_A11Hunstable

RTCCALIB_V1IDX_A11Lunstable

RTCCALIB_V1IDX_A12Hunstable

RTCCALIB_V1IDX_A12Lunstable

RTCCALIB_V1IDX_A13Hunstable

RTCCALIB_V1IDX_A13Lunstable

RTCCALIB_V1IDX_A20Hunstable

RTCCALIB_V1IDX_A20Lunstable

RTCCALIB_V1IDX_A21Hunstable

RTCCALIB_V1IDX_A21Lunstable

RTCCALIB_V1IDX_A22Hunstable

RTCCALIB_V1IDX_A22Lunstable

RTCCALIB_V1IDX_A23Hunstable

RTCCALIB_V1IDX_A23Lunstable

SECURE_BOOT_AGGRESSIVE_REVOKEunstable

Set this bit to enable aggressive secure boot key revocation mode

SECURE_BOOT_ENunstable

Set this bit to enable secure boot

SECURE_BOOT_KEY_REVOKE0unstable

Revoke 1st secure boot key

SECURE_BOOT_KEY_REVOKE1unstable

Revoke 2nd secure boot key

SECURE_BOOT_KEY_REVOKE2unstable

Revoke 3rd secure boot key

SECURE_VERSIONunstable

Secure version (used by ESP-IDF anti-rollback feature)

SOFT_DIS_JTAGunstable

Software disables JTAG. When software disabled; JTAG can be activated temporarily by HMAC peripheral

SPI_BOOT_CRYPT_CNTunstable

Enables flash encryption when 1 or 3 bits are set and disabled otherwise

SPI_PAD_CONFIG_CLKunstable

SPI_PAD_configure CLK

SPI_PAD_CONFIG_CSunstable

SPI_PAD_configure CS

SPI_PAD_CONFIG_Dunstable

SPI_PAD_configure D(D0)

SPI_PAD_CONFIG_D4unstable

SPI_PAD_configure D4

SPI_PAD_CONFIG_D5unstable

SPI_PAD_configure D5

SPI_PAD_CONFIG_D6unstable

SPI_PAD_configure D6

SPI_PAD_CONFIG_D7unstable

SPI_PAD_configure D7

SPI_PAD_CONFIG_DQSunstable

SPI_PAD_configure DQS

SPI_PAD_CONFIG_HDunstable

SPI_PAD_configure HD(D3)

SPI_PAD_CONFIG_Qunstable

SPI_PAD_configure Q(D1)

SPI_PAD_CONFIG_WPunstable

SPI_PAD_configure WP(D2)

SYS_DATA_PART0_2unstable

Stores the second part of the zeroth part of system data

TEMP_CALIBunstable

Temperature calibration data

UART_PRINT_CHANNELunstable

Selects the default UART for printing boot messages

UART_PRINT_CONTROLunstable

Set the default UART boot message output mode

USB_DREFHunstable

Controls single-end input threshold vrefh; 1.76 V to 2 V with step of 80 mV; stored in eFuse

USB_DREFLunstable

Controls single-end input threshold vrefl; 0.8 V to 1.04 V with step of 80 mV; stored in eFuse

USB_EXCHG_PINSunstable

Set this bit to exchange USB D+ and D- pins

USB_EXT_PHY_ENABLEunstable

Set this bit to enable external USB PHY

USB_FORCE_NOPERSISTunstable

If set; forces USB BVALID to 1

VDD_SPI_DCAPunstable

Prevents SPI regulator from overshoot

VDD_SPI_DCURLIMunstable

Tunes the current limit threshold of SPI regulator when tieh=0; about 800 mA/(8+d)

VDD_SPI_DREFHunstable

SPI regulator high voltage reference

VDD_SPI_DREFLunstable

SPI regulator low voltage reference

VDD_SPI_DREFMunstable

SPI regulator medium voltage reference

VDD_SPI_ENCURLIMunstable

Set SPI regulator to 1 to enable output current limit

VDD_SPI_EN_INITunstable

Set SPI regulator to 0 to configure init[1:0]=0

VDD_SPI_FORCEunstable

Set this bit to use XPD_VDD_PSI_REG and VDD_SPI_TIEH to configure VDD_SPI LDO

VDD_SPI_INITunstable

Adds resistor from LDO output to ground

VDD_SPI_MODECURLIMunstable

SPI regulator switches current limit mode

VDD_SPI_TIEHunstable

If VDD_SPI_FORCE is 1; determines VDD_SPI voltage

VDD_SPI_XPDunstable

If VDD_SPI_FORCE is 1; this value determines if the VDD_SPI regulator is powered on

WAFER_VERSION_MAJORunstable

WAFER_VERSION_MAJOR

WAFER_VERSION_MINOR_HIunstable

WAFER_VERSION_MINOR most significant bit

WAFER_VERSION_MINOR_LOunstable

WAFER_VERSION_MINOR least significant bits

WDT_DELAY_SELunstable

RTC watchdog timeout threshold; in unit of slow clock cycle

WR_DISunstable

Disable programming of individual eFuses

Functions

base_mac_addressunstable

Returns the base MAC address programmed into eFuse during manufacturing.

chip_revision

Returns the hardware revision.

flash_encryptionunstable

Get status of SPI boot encryption.

interface_mac_address

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

major_chip_versionunstable

Returns the major hardware revision

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

rtc_calib_cal_codeunstable

Get ADC reference point digital code for specified attenuation

rtc_calib_cal_mvunstable

Get ADC reference point voltage for specified attenuation in millivolts

rtc_calib_init_codeunstable

Get ADC initial code for specified attenuation from efuse

rtc_calib_readingunstable

Reads a parsed RTC calibration table value.

rtc_calib_versionunstable

Get version of RTC calibration block

rwdt_multiplierunstable

Get the multiplier for the timeout value of the RWDT STAGE 0 register.