Module flash 

Flash memory (FLASH)

Flash gives access to the whole internal flash, addressed by offsets from FLASH_BASE. Flash::into_regions and Flash::into_blocking_regions split it into one driver per flash region (bank, or group of equally sized sectors), which can be handed to different parts of the application.

The driver is shared by all families. Writes are done in units of WRITE_SIZE bytes, which is the native program unit of the chip (a half-word on F0/F1/F3, a 256-bit flash word on H7, …), and erases are done per sector/page.

ECC

Many families protect each flash word with an error correction code:

• Single-bit errors are corrected transparently.
• Two (or more) bit errors can’t be corrected. The read fails with Error::Ecc.

With the Cortex-M7 data cache enabled, a read also fails when another flash word of the same 32-byte cache line has an uncorrectable error.

EDATA

On H5 and C5, part of the flash can be used as EDATA (“flash high-cycle data” on H5): flash with 16-bit words and a higher endurance, meant for storing data. It is enabled in the option bytes (EDATA_EN on C5, EDATA1_EN/EDATA1_STRT and EDATA2_EN/EDATA2_STRT on H5). FlashLayout::edata_bank1 and FlashLayout::edata_bank2 are Edata drivers for the EDATA area of each bank.

EEPROM

L0 and L1 have a data EEPROM, which can be rewritten without erasing it first. FlashLayout::eeprom is an Eeprom driver for it.

Structs

Bank1Region

Bank2Region

Config

Flash driver configuration.

Flash

Internal flash memory driver.

FlashLayout

FlashRegion

Flash memory region

FlashSector

Flash sector.

InterruptHandler

Flash interrupt handler.

Enums

EraseParallelism

Parallelism used for flash erase operations.

Error

Flash error

FlashBank

Flash bank.

Constants

BANK1_REGION

BANK2_REGION

FLASH_BASE

FLASH_REGIONS

FLASH_SIZE

MAX_ERASE_SIZE

READ_SIZE

Read size (always 1)

WRITE_SIZE

Functions

banks_swapped

Returns whether flash banks 1 and 2 are currently swapped in the memory map.

get_flash_regions

Get all flash regions.