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Diffstat (limited to 'docs/eeprom_driver.md')
| -rw-r--r-- | docs/eeprom_driver.md | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/docs/eeprom_driver.md b/docs/eeprom_driver.md index 5a91a7c2d..188b95caa 100644 --- a/docs/eeprom_driver.md +++ b/docs/eeprom_driver.md @@ -1,4 +1,4 @@ -# EEPROM Driver Configuration +# EEPROM Driver Configuration :id=eeprom-driver-configuration The EEPROM driver can be swapped out depending on the needs of the keyboard, or whether extra hardware is present. @@ -6,15 +6,20 @@ Driver | Description -----------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- `EEPROM_DRIVER = vendor` (default) | Uses the on-chip driver provided by the chip manufacturer. For AVR, this is provided by avr-libc. This is supported on ARM for a subset of chips -- STM32F3xx, STM32F1xx, and STM32F072xB will be emulated by writing to flash. STM32L0xx and STM32L1xx will use the onboard dedicated true EEPROM. Other chips will generally act as "transient" below. `EEPROM_DRIVER = i2c` | Supports writing to I2C-based 24xx EEPROM chips. See the driver section below. +`EEPROM_DRIVER = spi` | Supports writing to SPI-based 25xx EEPROM chips. See the driver section below. `EEPROM_DRIVER = transient` | Fake EEPROM driver -- supports reading/writing to RAM, and will be discarded when power is lost. -## Vendor Driver Configuration +## Vendor Driver Configuration :id=vendor-eeprom-driver-configuration + +#### STM32 L0/L1 Configuration :id=stm32l0l1-eeprom-driver-configuration !> Resetting EEPROM using an STM32L0/L1 device takes up to 1 second for every 1kB of internal EEPROM used. -No configurable options are available. +`config.h` override | Description | Default Value +------------------------------------|--------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------- +`#define STM32_ONBOARD_EEPROM_SIZE` | The size of the EEPROM to use, in bytes. Erase times can be high, so it's configurable here, if not using the default value. | Minimum required to cover base _eeconfig_ data, or `1024` if VIA is enabled. -## I2C Driver Configuration +## I2C Driver Configuration :id=i2c-eeprom-driver-configuration Currently QMK supports 24xx-series chips over I2C. As such, requires a working i2c_master driver configuration. You can override the driver configuration via your config.h: @@ -41,7 +46,21 @@ MB85RC256V FRAM | `#define EEPROM_I2C_MB85RC256V` | <https://www.adafruit.com/p ?> If you find that the EEPROM is not cooperating, ensure you've correctly shifted up your EEPROM address by 1. For example, the datasheet might state the address as `0b01010000` -- the correct value of `EXTERNAL_EEPROM_I2C_BASE_ADDRESS` needs to be `0b10100000`. -## Transient Driver configuration +## SPI Driver Configuration :id=spi-eeprom-driver-configuration + +Currently QMK supports 25xx-series chips over SPI. As such, requires a working spi_master driver configuration. You can override the driver configuration via your config.h: + +`config.h` override | Description | Default Value +-----------------------------------------------|--------------------------------------------------------------------------------------|-------------- +`#define EXTERNAL_EEPROM_SPI_SLAVE_SELECT_PIN` | SPI Slave select pin in order to inform that the EEPROM is currently being addressed | _none_ +`#define EXTERNAL_EEPROM_SPI_CLOCK_DIVISOR` | Clock divisor used to divide the peripheral clock to derive the SPI frequency | `64` +`#define EXTERNAL_EEPROM_BYTE_COUNT` | Total size of the EEPROM in bytes | 8192 +`#define EXTERNAL_EEPROM_PAGE_SIZE` | Page size of the EEPROM in bytes, as specified in the datasheet | 32 +`#define EXTERNAL_EEPROM_ADDRESS_SIZE` | The number of bytes to transmit for the memory location within the EEPROM | 2 + +!> There's no way to determine if there is an SPI EEPROM actually responding. Generally, this will result in reads of nothing but zero. + +## Transient Driver configuration :id=transient-eeprom-driver-configuration The only configurable item for the transient EEPROM driver is its size: |