STM32H7 - MPU Configuration
Hi All,
I was testing my new STM32H746XIH6 board and met the post below by @GSpre.1 during a search about SDRAM performance.
GSpre.1 - Performance characteristics of SDRAM on STM32F7508-DISCO board
I don't have a lot of time to read MPU documentation, maybe someone has an idea about the code piece below that @GSpre.1 adviced.
I did not perform a precise measurement but used Systick for both internal and external (32-bit SDRAM) memory array manipulation time for the same data length. (I-Cache and D-Cache are both enabled as expected.)
Internal memory test: 12ms
External memory test: 47ms without the code below
External memory test: 13ms.with the code below
* What exactly the code below does ?
* Am I compromising from anything for speed ?
There are a lot of job to do during board bring-up I have no time to read a lot of documentation. I will be appreciated if someone share experience...
BTW, thanks for sharing @GSpre.1
Regars.
MPU_Region_InitTypeDef MPU_InitStruct;
HAL_MPU_Disable();
MPU_InitStruct.Enable = MPU_REGION_ENABLE;
MPU_InitStruct.BaseAddress = 0xD0000000;
MPU_InitStruct.Size = MPU_REGION_SIZE_32MB;
MPU_InitStruct.AccessPermission = MPU_REGION_FULL_ACCESS;
MPU_InitStruct.IsBufferable = MPU_ACCESS_BUFFERABLE;
MPU_InitStruct.IsCacheable = MPU_ACCESS_CACHEABLE;
MPU_InitStruct.IsShareable = MPU_ACCESS_NOT_SHAREABLE;
MPU_InitStruct.Number = MPU_REGION_NUMBER0;
MPU_InitStruct.TypeExtField = MPU_TEX_LEVEL1;
MPU_InitStruct.SubRegionDisable = 0x00;
MPU_InitStruct.DisableExec = MPU_INSTRUCTION_ACCESS_DISABLE;
HAL_MPU_ConfigRegion(&MPU_InitStruct);
HAL_MPU_Enable(MPU_PRIVILEGED_DEFAULT);
