STM32F7: use of DMA to change CCR1 of timer gives transfer error

Posted on July 08, 2016 at 08:11

Hi all,

I use DMA and linked timers in most of my projects with no problems on STM32F1 and STM32F4. I want to do the same on the STM32F7. 

As a test I want to use a DMA stream to create a changing signal on a PWM output. When I debug the code I see that the DMA has a transfer error but I don't understand why. Here is my initialisation code (which with some minor changes works on STM32F1):

            RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);          

            DMA_Cmd(DMA1_Stream7, DISABLE);

            

            DMA_DeInit(DMA1_Stream7);

            DMA_InitStruct.DMA_Channel = DMA_Channel_3;

            DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t)(&(TIM10->CCR1));

            DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t)&sintab_wa;

            DMA_InitStruct.DMA_DIR = DMA_DIR_MemoryToPeripheral;

            DMA_InitStruct.DMA_BufferSize = (uint32_t)nsamp_;

            DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

            DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;

            DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;

            DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;

            DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;

            DMA_InitStruct.DMA_Priority = DMA_Priority_High;

            DMA_InitStruct.DMA_FIFOMode = DMA_FIFOMode_Disable;

            DMA_InitStruct.DMA_FIFOThreshold = DMA_FIFOThreshold_1QuarterFull;

            DMA_InitStruct.DMA_MemoryBurst = DMA_MemoryBurst_Single;

            DMA_InitStruct.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;

            

            /* Wait for  DMA_GetCmdStatus() */            

            while(DMA_GetCmdStatus(DMA1_Stream7) != DISABLE)

            {}

            

            /* Flush cashes to memory and wait for flush to complete */

            SCB_CleanDCache();

              

            DMA_Init(DMA1_Stream7, &DMA_InitStruct);  

            

            /* Enable DMA1 channel3 */

            DMA_Cmd(DMA1_Stream7, ENABLE);

I have both instruction and data cache enabled, is that what's blocking? Can anyone give me some clue why I get the bus error?

Thanks,

Andre

#stm32f7-dma-timer