DocID17922 Rev 6

9/18

STM8AL3xxx STM8L052R8 STM8L1xxx6/8

Silicon limitations

17

Workaround 3

This workaround can be used if block erase cannot be replaced by block programming.

In this workaround, DMA is used to transfer data to the EEPROM instead of the core. All

other DMA transfers are delayed once the core is stalled due to data transfer to memory

controller.

/* start of the workaround in user code, using FW Library */

#ifdef USE_EVENT_MODE

DMA1_Channel3->CCR= DMA_CCR_MEM | DMA_CCR_IDM | DMA_CCR_TCIE;

/*

Config DMA Chn3 Mem, incr, disable, interrupt) */

#else

DMA1_Channel3->CCR= DMA_CCR_MEM | DMA_CCR_IDM;

/* Config DMA

Chn3 (Mem, incr,disable) */

#endif

DMA1_Channel3->CM0ARH= (uint8_t)0;

/* Source address */

DMA1_Channel3->CM0ARL= (uint8_t)0;

DMA1_Channel3->CPARH= (uint8_t)(addr_begin >> 8); /* Destination

address */

DMA1_Channel3->CPARL= (uint8_t)(addr_begin);

DMA1_Channel3->CNBTR= 2; /* Number of data to be transferred */

DMA1_Channel3->CSPR= 8; /* Low priority, 16 bit mode */

DMA1_Channel3->CSPR &= ~DMA_CSPR_TCIF;/* Clear TCIF */

DMA1->GCSR|= 1; /* Global DMA enable */

#ifdef USE_EVENT_MODE

WFE->CR3 = WFE_CR3_DMA1CH23_EV; /* Enable event generation on

DMA */

#endif

FLASH->DUKR = 0xAE; /* Unprotect data memory */

FLASH->DUKR = 0x56;

while((FLASH->IAPSR & FLASH_IAPSR_DUL) == 0)

{} /* Polling DUL */

FLASH_Block_Load();

/* end of the workaround in user code */

/* following routine has to be placed in the RAM */

void FLASH_Block_Load(){

__asm("sim\n"); /* Disable interrupts */

FLASH->CR2 |= FLASH_CR2_ERASE; /* Enable erase block mode */

DMA1_Channel3->CCR|= DMA_CCR_CE; /* Enable DMA MEM transfer */

#ifdef USE_EVENT_MODE

__asm("wfe"); /* Wait for end of DMA operation */

#else

while((DMA1_Channel3->CSPR & DMA_CSPR_TCIF) == 0)

{} /* Polling for end of DMA operation */

#endif

__asm("rim\n"); /* Enable interrupts */

}