Posted on July 17, 2014 at 14:33
I thought that might be the problem, so tried to do it with a single transfer, but that doesn't work either. Here's the modified code for configuring the DMA:
//Set the DMA CR
tempreg = DMA_Channel_4 //Select Channel 4
| DMA_MemoryBurst_Single
| DMA_PeripheralBurst_Single
| DMA_Priority_VeryHigh //Priority is very_high
| DMA_MemoryDataSize_Word //Memory data size is 32bit (word)
| DMA_PeripheralDataSize_Word //Peripheral data size is 32bit (word)
| DMA_MemoryInc_Enable //Enable Memory Increment
| DMA_PeripheralInc_Disable //Disable Peripheral Increment
| DMA_Mode_Normal //Disable Circular mode
| ((dir == WRITE_TO_CARD) ? DMA_DIR_MemoryToPeripheral : DMA_DIR_PeripheralToMemory)
| DMA_FlowCtrl_Peripheral; //Peripheral controls the flow control. (The DMA tranfer ends when the data issues end of transfer signal regardless of ndtr value)
//Bit [4..1] is for interupt mask. I don't use interrupts here
//Bit 0 is EN. I will set it after I set the FIFO CR. (FIFO CR cannot be modified when EN=1)
DMA2_Stream3->CR = tempreg;
//Set the FIFO CR
tempreg = DMA_FIFOMode_Disable; //Fifo is disabled (Direct mode is Enabled);
DMA2_Stream3->FCR = tempreg;
#endif
//Enable the DMA (When it is enabled, it starts to respond dma requests)
DMA2_Stream3->CR |= DMA_SxCR_EN;
