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Jens Jonckheere
Jens Jonckheere
Associate
October 6, 2020
Solved

DMA2D configuration error IRQ after creating dynamic bitmap

  • October 6, 2020
  • 2 replies
  • 910 views

Hi,

I have a problem when using a dynamic bitmap (no problems in simulator, only on MCU).

No problems arise when calling the Bitmap::dynamicBitmapCreate() function, it returns a valid bitmap_id, but then when I set an Image with this bitmap_id, things go wrong.

We keep getting into the DMA2D_IRQHandler() untill the watchdog resets the MCU.

When inspecting the registers, I saw that in DMA2D->ISR the CEIF (configuration error) is set.

void DMA2D_IRQHandler(void)
{
 if (DMA2D->ISR & 2)
 {
 DMA2D->IFCR = 2;
 
 //invalidate D-Cache after DMA transfer
 SCB_CleanInvalidateDCache();
 
 touchgfx::HAL::getInstance()->signalDMAInterrupt();
 }

Does anyone have an idea what can be the problem?

Thanks in advance!

Kind regards,

Jens Jonckheere

Platform info:

  • STM32F767
  • 8 MB external SDRAM

This topic has been closed for replies.
Best answer by Jens Jonckheere

This problem was "solved" by changing:

HAL& hal = touchgfx_generic_init<STM32F7HAL>(dma, display, tc, 480, 272, (uint16_t*)bitmap_cache, sizeof(bitmap_cache), 1);

to:

HAL& hal = touchgfx_generic_init<STM32F7HAL>(dma, display, tc, 480, 272, (uint16_t*)bitmap_cache, sizeof(bitmap_cache), 4);

So by changing the param numberOfDynamicBitmaps in touchgfx_generic_init to 4, the function Bitmap::dynamicBitmapGetAddress() returns a 32-bit aligned address.

It's not a nice solution but it works because I only use 1 dynamic bitmap, so it will always return the same address, I hope.

I guess this is a bug in touchgfx, the address of a dynamic bitmap (atleast of type Bitmap::ARGB8888) should always be aligned I think. Otherwise it can give an error in the DMA2D peripheral.

This was in touchgfx version 4.12.3.

Kind regards,

Jens Jonckheere

2 replies

Jens Jonckheere
Jens JonckheereAuthor
Associate
October 7, 2020
uint8_t* ram_mask_data_uint8 = Bitmap::dynamicBitmapGetAddress(dynamic_bitmap_id);

I figured out that the address returned by Bitmap::dynamicBitmapGetAddress() is not 32-bit aligned.

This address is then used in the DMA2D->FGMAR (foreground memory address) register, which needs to be 32-bit aligned for 32-bit per pixel images. This triggers the configuration error interrupt.

Is this normal that Bitmap::dynamicBitmapGetAddress() can return an address that is not aligned? Or is something wrong in my configuration of touchgfx?

Jens Jonckheere
Jens JonckheereAuthorBest answer
Associate
October 7, 2020

This problem was "solved" by changing:

HAL& hal = touchgfx_generic_init<STM32F7HAL>(dma, display, tc, 480, 272, (uint16_t*)bitmap_cache, sizeof(bitmap_cache), 1);

to:

HAL& hal = touchgfx_generic_init<STM32F7HAL>(dma, display, tc, 480, 272, (uint16_t*)bitmap_cache, sizeof(bitmap_cache), 4);

So by changing the param numberOfDynamicBitmaps in touchgfx_generic_init to 4, the function Bitmap::dynamicBitmapGetAddress() returns a 32-bit aligned address.

It's not a nice solution but it works because I only use 1 dynamic bitmap, so it will always return the same address, I hope.

I guess this is a bug in touchgfx, the address of a dynamic bitmap (atleast of type Bitmap::ARGB8888) should always be aligned I think. Otherwise it can give an error in the DMA2D peripheral.

This was in touchgfx version 4.12.3.

Kind regards,

Jens Jonckheere

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