NVMS Virtual EPROM driver. More...

Files
file	ad_nvms_ves.h
	NVMS VES driver API.

Macros
#define	AD_NVMS_VES_CONTAINER_SIZE 64
	Default container size.

#define	AD_NVMS_VES_MULTIPLIER 8
	Default flash utilization multiplier. More...

#define	AD_NVMS_MAX_SECTOR_COUNT 256
	NVMS maximum sector count. More...

#define	AD_NVMS_VES_GC_THRESHOLD -1
	Garbage collector threshold. More...

Functions
void	ad_nvms_ves_init (void)
	Initialize NVMS Virtual EEPROM Storage driver. More...

Detailed Description

NVMS Virtual EPROM driver.

NVMS driver allows to use flash as Virtual EEPROM. Virtual EEPROM is stored on flash partition provides virtual addressing to store data to flash with wear leveling functionality. Each write to partition at given address will write different flash area. It also provides power failure safety.

Macro Definition Documentation

◆ AD_NVMS_MAX_SECTOR_COUNT

#define AD_NVMS_MAX_SECTOR_COUNT 256

NVMS maximum sector count.

If partition sector count exceeds 256, RAM usage for virtual address translation will double

◆ AD_NVMS_VES_GC_THRESHOLD

#define AD_NVMS_VES_GC_THRESHOLD -1

Garbage collector threshold.

Garbage collection threshold allows to choose when sector is allowed to be recycled. Sectors are recycled only if dirty container count is >= threshold.

Setting this to -1 will choose most dirty sector during garbage collection.

In practice this means that totally dirty sectors are recycled (no need to copy from old sector to new one). During random write stress tests some sector were written 8% more times than average.

Setting this to value grater than 0 allows to recycle sectors that still contain valid data. When those sectors are chosen data from partially written sectors is moved to new sector. In practice this mean that more sector erase operation will occur but wear leveling will treat sector more equal. During random write stress, test most often erased sector was 0.2% more used then average. Total sectors erase count was less then 1% higher then when most dirty sectors were strategy was used.

◆ AD_NVMS_VES_MULTIPLIER

#define AD_NVMS_VES_MULTIPLIER 8

Default flash utilization multiplier.

For flash size x available address space is:

Without CRC x / AD_NVMS_VES_MULTIPLIER / AD_NVMS_VES_CONTAINER_SIZE * (AD_NVMS_VES_CONTAINER_SIZE - 2).
With CRC x / AD_NVMS_VES_MULTIPLIER / AD_NVMS_VES_CONTAINER_SIZE * (AD_NVMS_VES_CONTAINER_SIZE - 4).

Function Documentation

◆ ad_nvms_ves_init()

void ad_nvms_ves_init ( void )

Initialize NVMS Virtual EEPROM Storage driver.

Files

Macros