About DMA...

[tony55723]

Hello ,

I use SDK 15.3, chip is nRF52811

If I want to use DMA+SPI, is there a reference example?

Is this DMA called easyDMA?

Thanks

[Simonr]

Hi Tony

Yes, there should be multiple SPI examples in the \..\SDK15.3\examples\peripheral folder, and you should be able to enable DMA (EasyDMA) on all of them using the sdk_config.h file.

Best regards,

Simon

[tony55723]

Hi,

Thank you for your reply.

I still don't understand

In sdk_config.h, I did find easyDMA

Then, in main.c, the while(1) loop inside the main function

Have the following line of code

nrf_drv_spi_transfer(&spi, m_tx_buf, m_length, m_rx_buf, m_length)

This SPI transmission method is DMA?

Thank you.

[Simonr]

Hi

Correct, when SPI_USE_EASY_DMA is enabled the SPI transactions will use (Easy)DMA. You should be able to confirm it by seeing a small current increase when EasyDMA is enabled, as opposed to when this is disabled. And yes, this is the only necessary step to enable/disable DMA in the SPI example.

Best regards,

Simon