In stm32l4xx_hal.c, there is a bug with HAL_SYSCFG_EnableMemorySwappingBank().

[pgspro1]

The code is identical to the Disable version. The enable swapping is currently this:

void HAL_SYSCFG_EnableMemorySwappingBank(void)

{

 *(__IO uint32_t *)FB_MODE_BB = 0x00000000UL;

}

 and instead of = 0, it should be the equivalent of 0x100.

Also, the lower 3-bits should be maintained since they are MEM_MODE bits. As it turns out, %000 is Main Flash memory, which is probably good for most, but it's still a bad implementation.

[Imen.D]

Hello,

We will check this issue internally and we will come back to you.

Kind Regards,

Imen

[Imen.D · Accepted solution]

Hi @pgspro1​ ,

This is a Bit Banding access, not a full register access.

/* Alias word address of FB_MODE bit */
#define MEMRMP_OFFSET             SYSCFG_OFFSET
#define FB_MODE_BitNumber         8U
#define FB_MODE_BB                (PERIPH_BB_BASE + (MEMRMP_OFFSET * 32U) + (FB_MODE_BitNumber * 4U))

So, there is a bug and the fix should be :

void HAL_SYSCFG_EnableMemorySwappingBank(void)
{
  *(__IO uint32_t *)FB_MODE_BB = 0x00000001UL;
}

Avantage of the bit banding, No effects on the other bits of the SYSCFG_MEMRMP register with this single instruction.

Thanks for highlighting this issue.

Kind Regards,

Imen.

[Imen.D]

Hello,

This issue is fixed with the new release of STM32CubeL4 V1.14.0 available on the ST web site.

Regards,

Imen.