Unlocking and erasing protected flash on PY32 chips

[kholia]

Hi,

I am experimenting with flash protection on PY32 chips with the following program:

#include <string.h>
#include "main.h"
#include "py32f0xx_bsp_clock.h"
#include "py32f0xx_bsp_printf.h"

static void APP_GPIOConfig(void);

static void APP_FlashSetOptionBytes(void)
{
  FLASH_OBProgramInitTypeDef OBInitCfg;

  LL_FLASH_Unlock();
  LL_FLASH_OB_Unlock();

  OBInitCfg.OptionType = OPTIONBYTE_USER;
  OBInitCfg.USERType = OB_USER_BOR_EN | OB_USER_BOR_LEV | OB_USER_IWDG_SW | OB_USER_WWDG_SW | OB_USER_NRST_MODE | OB_USER_nBOOT1;
  OBInitCfg.USERConfig = OB_BOR_DISABLE | OB_BOR_LEVEL_3p1_3p2 | OB_IWDG_SW | OB_WWDG_SW | OB_RESET_MODE_RESET | OB_BOOT1_SYSTEM;
  LL_FLASH_OBProgram(&OBInitCfg);

  LL_FLASH_OB_RDP_LevelConfig(OB_RDP_LEVEL_1);

  LL_FLASH_Lock();
  LL_FLASH_OB_Lock();
  /* Reload option bytes */
  LL_FLASH_OB_Launch();
}

int main(void)
{
  /* Set clock = 8MHz */
  BSP_RCC_HSI_8MConfig();

  /* Enable peripheral clock */
  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA | LL_IOP_GRP1_PERIPH_GPIOB);

  BSP_USART_Config(115200);
  printf("SPI Demo: nRF24L01 Wireless\r\nClock: %ld\r\n", SystemCoreClock);

  APP_GPIOConfig();

  LL_mDelay(7000);

  uint32_t rdplvl = READ_BIT(FLASH->OPTR, FLASH_OPTR_RDP);
  if (rdplvl == OB_RDP_LEVEL_0) {
    APP_FlashSetOptionBytes();
  }
  else
  {
    printf("RESET has been configurated as RESET\r\n");
  }

  while (1)
  {
    printf("nRF24L01 check: error\r\n");
    LL_mDelay(2000);
  }
}

static void APP_GPIOConfig(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct;

  // PA6 CSN
  LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_6, LL_GPIO_MODE_OUTPUT);
  // PA5 CE
  LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_5, LL_GPIO_MODE_OUTPUT);
  /* PA4 as input */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_4;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_UP;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

void APP_ErrorHandler(void)
{
  while (1);
}

#ifdef  USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
  while (1);
}
#endif /* USE_FULL_ASSERT */

After power-cycling the PY32 chip (FY32F003 in SOP-8 package), I can no longer erase the chip using J-Link.

Is there a known method to Unlock and Erase the protected flash memory on PY32 chips?

https://dzone.com/articles/unlocking-and-erasing-flash is a good read on this topic but I didn't find a method which works for PY32 chips yet.

Thanks for the help.