H7 cant write a FMC 16bit word once

[Trevor Jones]

if someone can tell me how to write a byte to a FMC memory ?

Reading a 16bit word looks correct and I can read the status correctly

but using A0 as register select, this is writing one 16bit word,

it seems to write 4 times, A0 is jumping up and down,

It doesn't work on my external LCD chip.

[waclawek.jan]

Is the FMC area in question cached?

See also https://community.st.com/s/question/0D50X0000B42x2iSQA/stm32h743iit6-fmc-ne-producing-multiple-clocks

JW

[Trevor Jones]

Yes, the Data cache is turned off.

will check your link,

yes it is fixed now.

thanks for that

void MPU_Config(void)
{
  MPU_Region_InitTypeDef MPU_InitStruct = {0};
 
  /* Disables the MPU */
  HAL_MPU_Disable();
  /** Initializes and configures the Region and the memory to be protected 
  */
  MPU_InitStruct.Enable = MPU_REGION_ENABLE;
  MPU_InitStruct.Number = MPU_REGION_NUMBER7;
  MPU_InitStruct.BaseAddress = 0x60000000;
  MPU_InitStruct.Size = MPU_REGION_SIZE_32B;
  MPU_InitStruct.SubRegionDisable = 0x0;
  MPU_InitStruct.TypeExtField = MPU_TEX_LEVEL0;
  MPU_InitStruct.AccessPermission = MPU_REGION_FULL_ACCESS;
  MPU_InitStruct.DisableExec = MPU_INSTRUCTION_ACCESS_ENABLE;
  MPU_InitStruct.IsShareable = MPU_ACCESS_NOT_SHAREABLE;
  MPU_InitStruct.IsCacheable = MPU_ACCESS_NOT_CACHEABLE;
  MPU_InitStruct.IsBufferable = MPU_ACCESS_NOT_BUFFERABLE;
 
  HAL_MPU_ConfigRegion(&MPU_InitStruct);
  /* Enables the MPU */
  HAL_MPU_Enable(MPU_HFNMI_PRIVDEF);
 
}