I use STM32H735 and her backup memory at 0x3880_0000 (4KB). All works OK if I use SCB_CleanDCache_by_Addr(0x38800000, 4096) after a write. Is it possible to disable dcache in this area ?

PMina.2 · ‎2022-10-25

I tried to configure MPU using standard configuration generated.

I tried this code

MPU_Region_InitTypeDef MPU_InitStruct;
 
HAL_MPU_Disable();
 
/* Configure the MPU as Strongly ordered for not defined regions */
MPU_InitStruct.Enable = MPU_REGION_ENABLE;
MPU_InitStruct.BaseAddress = 0x00;
MPU_InitStruct.Size = MPU_REGION_SIZE_4GB;
MPU_InitStruct.AccessPermission = MPU_REGION_NO_ACCESS;
MPU_InitStruct.IsBufferable = MPU_ACCESS_NOT_BUFFERABLE;
MPU_InitStruct.IsCacheable = MPU_ACCESS_NOT_CACHEABLE;
MPU_InitStruct.IsShareable = MPU_ACCESS_SHAREABLE;
MPU_InitStruct.Number = MPU_REGION_NUMBER0;
MPU_InitStruct.TypeExtField = MPU_TEX_LEVEL0;
MPU_InitStruct.SubRegionDisable = 0x87;
MPU_InitStruct.DisableExec = MPU_INSTRUCTION_ACCESS_DISABLE;
HAL_MPU_ConfigRegion(&MPU_InitStruct);
 
HAL_MPU_Enable(MPU_PRIVILEGED_DEFAULT);

and other

MPU_InitStruct.BaseAddress = 0x38800000;

MPU_InitStruct.Size = MPU_REGION_SIZE_4B;

and adding an other region, but it does not work.

Tried also SCB_DisableDCache.

Have you got some suggestion ?

Thanks for your time and support.

Best regards,

Paolo