STM32F446 DMA Mem to GPIO

[daniel2]

Posted on August 12, 2015 at 02:12

I have the example from the library showing DMA (mem to mem) working with the following initialization:

/* Configure DMA Stream */
DMA_InitStructure.DMA_Channel = DMA_CHANNEL; 
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)aSRC_Const_Buffer;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)aDST_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToMemory;
DMA_InitStructure.DMA_BufferSize = (uint32_t)BUFFER_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Enable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; 
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA_STREAM, &DMA_InitStructure);

I'm trying to adapt it to write to GPIOC, as follows but it's not working. Is there anything else I need to change? I can write to GPIOC->ODR manually and I see the lines toggle.

/* Configure DMA Stream */
DMA_InitStructure.DMA_Channel = DMA_CHANNEL;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&GPIOC->ODR;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)aSRC_Const_Buffer2;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = (uint32_t)BUFFER_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA_STREAM, &DMA_InitStructure);

[Tesla DeLorean]

Posted on August 13, 2015 at 00:59

DMA1 connects with APB1 slaves

DMA2 connects with APB2 slaves''The DMA1 controller AHB peripheral port is not connected to the bus matrix like DMA2 controller.''

[daniel2]

Posted on August 13, 2015 at 01:33

For whatever reason TIM8 doesn't appear to have a CC IRQn on the STM32F446

TIM8_BRK_IRQn = 43, /*!< TIM8 Break Interrupt */
TIM8_BRK_TIM12_IRQn = 43, /*!< TIM8 Break Interrupt and TIM12 global interrupt */
TIM8_UP_TIM13_IRQn = 44, /*!< TIM8 Update Interrupt and TIM13 global interrupt */
TIM8_TRG_COM_TIM14_IRQn = 45, /*!< TIM8 Trigger and Commutation Interrupt and TIM14 global interrupt */

If I enable the CC1 and CC2 interrupts for TIM8, they do appear to trigger in the TIM8_UP_TIM13_IRQn, but they are triggering at the same time as the update so I'm not sure what's going on there. I'm going to try switching to TIM1, which has the correct update and see if the DMA still works.

[Tesla DeLorean]

Posted on August 13, 2015 at 01:57

startup_stm32f446xx.s

...
DCD OTG_FS_WKUP_IRQHandler ; USB OTG FS Wakeup through EXTI line
DCD TIM8_BRK_TIM12_IRQHandler ; TIM8 Break and TIM12
DCD TIM8_UP_TIM13_IRQHandler ; TIM8 Update and TIM13
DCD TIM8_TRG_COM_TIM14_IRQHandler ; TIM8 Trigger and Commutation and TIM14
DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare
DCD DMA1_Stream7_IRQHandler ; DMA1 Stream7
...

stm32f4xx.h (446 section)

...
OTG_FS_WKUP_IRQn = 42, /*!< USB OTG FS Wakeup through EXTI line interrupt */
TIM8_BRK_IRQn = 43, /*!< TIM8 Break Interrupt */
TIM8_BRK_TIM12_IRQn = 43, /*!< TIM8 Break Interrupt and TIM12 global interrupt */
TIM8_UP_TIM13_IRQn = 44, /*!< TIM8 Update Interrupt and TIM13 global interrupt */
TIM8_TRG_COM_TIM14_IRQn = 45, /*!< TIM8 Trigger and Commutation Interrupt and TIM14 global interrupt */
DMA1_Stream7_IRQn = 47, /*!< DMA1 Stream7 Interrupt */
...

I think something is hosed up there, TWO TIM8_BRK interrupts. Will consult the DM and RM Try: TIM8_CC_IRQn = 46, /*!< TIM8 Capture Compare Interrupt */

[Tesla DeLorean]

Posted on August 13, 2015 at 02:12

RM0390

[daniel2]

Posted on August 13, 2015 at 04:57

Oh yeah.. wow, good catch! I guess that's what I get for using such a new part :p Oh well I got TIM1 working now.