boot application - issue with SCB_DisableDCache

[Anand Ram]

does anybody have a idea why the code is stuck at below do while loop (bold marked)?.

use case: for the boot application , SCB_DisableDCache () is getting called before jumping into use aplication.

__STATIC_INLINE void SCB_DisableDCache (void)

{

 #if defined (__DCACHE_PRESENT) && (__DCACHE_PRESENT == 1U)

  uint32_t ccsidr;

  uint32_t sets;

  uint32_t ways;

  SCB->CSSELR = 0U; /*(0U << 1U) | 0U;*/ /* Level 1 data cache */

  __DSB();

  SCB->CCR &= ~(uint32_t)SCB_CCR_DC_Msk; /* disable D-Cache */

  __DSB();

  ccsidr = SCB->CCSIDR;

                      /* clean & invalidate D-Cache */

  sets = (uint32_t)(CCSIDR_SETS(ccsidr));

  do {

   ways = (uint32_t)(CCSIDR_WAYS(ccsidr));

   do {

    SCB->DCCISW = (((sets << SCB_DCCISW_SET_Pos) & SCB_DCCISW_SET_Msk) |

            ((ways << SCB_DCCISW_WAY_Pos) & SCB_DCCISW_WAY_Msk) );

    #if defined ( __CC_ARM )

     __schedule_barrier();

    #endif

   } while (ways-- != 0U);

  } while(sets-- != 0U);

  __DSB();

  __ISB();

 #endif

}

[Pavel A.]

Was DCache enabled before you call this?

Are you trying to step thru this function in debugger?

-- pa

[Piranha]

Haven't sorted out the exact reason behind it, but cache management functions tend to stuck if you try to debug them by stepping in or even stepping over with a single step. Just let them run normally and use breakpoints to stop at specific code.

[Anand Ram]

hi , yes i have enabled DCache during init and disabled again in deinit process before jumping into application software.

no, i just let it running and tried without debugger after flashing too, while debugging its observed code is breaking at i mentioned before.

[Anand Ram]

hi Piranha, yes tried the same still issue persists.

[Anand Ram]

additional info, i use the RAM location to fill the data using linker commands in c file after the necessary configurations in .id file.

do i need to do any sort of memory configurations as below

 HAL_MPU_ConfigRegion(&MPU_InitStruct); ??

[Anand Ram]

still this issue is not solved?please share your valuable inputs to find the root cause and fix

[upanie]

Hi,

Did you solve the problem?

I have exactly the same behavior in this project:

https://github.com/STMicroelectronics/STM32CubeF7/tree/master/Projects/STM32F7508-DISCO/Templates/Template_Project

It works fine on STM32F7508-DISCO board but stuck in SCB_DisableDCache (void) on my custom board.

The difference is the microcontroller used. On STM32F7508-DISCO there is STM32F750N8 and on my board I have STM32F750V8.

But I can't find any difference between those chips that could affect DCache invalidating.

[Anand Ram]

hi,

please include below part of code during deinit.

SCB_DisableICache();

 SCB_DisableDCache();

 SCB_CleanDCache();

 SCB_InvalidateICache();

 SCB_InvalidateDCache();

alternative workaround :

if you have big size array or accessing variables, please use volatile keyword. which don't use cache memory.

Reason for the problem: cache is not cleared properly during de-init procedure.

hope this information helps you.

-Anandh Ram

[upanie]

Thanks so much. I'll check this out today and let you know if it worked.