Callback eDMA

carloscardenal — Thu, 07 Sep 2017 14:45:47 GMT

Hi,

I am using eDMA to transfer from peripheral to memory (one register value) and I don't want to use the callback function, so I disable interrupts but still I need to set up the callback function and a global variable in order to transfer all data.

There is any way of getting rid of EDMA_SetCallback() in SDK 2.0?

Re: Callback eDMA

jorge_a_vazquez — Thu, 14 Sep 2017 00:11:23 GMT

Hi carlos cardenal

There is no need to set a callback to work with the eDMA driver, for example check the example code provided in SDK drivers;

EDMA_GetDefaultConfig(&userConfig);
EDMA_Init(DMA0, &userConfig);
EDMA_CreateHandle(&g_EDMA_Handle, DMA0, 0);
EDMA_SetCallback(&g_EDMA_Handle, EDMA_Callback, NULL);
EDMA_PrepareTransfer(&transferConfig, srcAddr, sizeof(srcAddr[0]), destAddr, sizeof(destAddr[0]),
                         sizeof(srcAddr[0]), sizeof(srcAddr), kEDMA_MemoryToMemory);
EDMA_SubmitTransfer(&g_EDMA_Handle, &transferConfig);
EDMA_StartTransfer(&g_EDMA_Handle);‍‍‍‍‍‍‍‍

If you comment the EDMA_SetCallback line, the DMA transfers still happen, you only will not have a function that is called when transfer finished.

Please remember that if you are using transfer to internal memory, your variable addresses need to be aligned, for example:

uint16_t Your_internal_buffer[BUFF_LENGTH] __attribute__ ((aligned (32)));‍‍

Hope this information could help you.
Have a great day,
Jorge Alcala

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topic Callback eDMA in Kinetis Software Development Kit

Callback eDMA

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