topic Re: spi's dma mode receive data successfully but send data failed. in S32K

spi's dma mode receive data successfully but send data failed.

vanaua — Tue, 19 May 2020 08:15:56 GMT

Dear all:

I had a problem with using spi's dma mode for host and slave communication. I did not use the SDK, but programmed it directly by reading and writing registers . In the following code, I tried to use s32k116 that was set as a slave device to communicate with the external spi host device,however, While the host keeps sending 128 bytes of data, the slave DMA receive interrupt could be triggered and receive data from the host, however, the oscilloscope found that the output pin from the slave machine shows no waveform, In other words, DMA transmiting of slave failed.could you help me find out where the problem is? Thank you very much.

Re: spi's dma mode could not receive or send data

vanaua — Tue, 19 May 2020 08:58:27 GMT

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Re: spi's dma mode receive data successfully but send data failed.

danielmartynek — Fri, 22 May 2020 08:35:11 GMT

Hello vanaua@163.com,

I just quickly tested your code and there is a configuration error in the DMA ch0.

BR, Daniel

Re: spi's dma mode receive data successfully but send data failed.

vanaua — Mon, 25 May 2020 03:18:21 GMT

Hi, Thank you for your reply. I found that there was a error with the code I uploaded earlier. Such as

DMA->TCD[0].SADDR = DMA_TCD_SADDR_SADDR(&(LPSPI0->RDR)); /* Source Address. */

and the other.(the red is correct)

I have changed it to be more perfect. However, slave's LPSPI communication with DMA can only receive data, but cannot send data. I can not figure out what kind of BUG cause this error.

Re: spi's dma mode receive data successfully but send data failed.

vanaua — Tue, 26 May 2020 01:48:02 GMT

According to my understanding, Data from the array of TCD1_Send was transmitted to the register of LPSPI0 - > TDR in the channel 1 of DMA .And in fact, the channel is sent with receiving channel under one same clock, so when receiving channel 0 transmission complete interruption was trigged, channel 1 send has been completed as well. However, I don't see any output data sent from the pin during this period.

Re: spi's dma mode receive data successfully but send data failed.

vanaua — Tue, 26 May 2020 01:50:42 GMT

What's more, Whether LPSPI slaves support sending DMA messages or not was still confusing me, But I was following the manual of S32K-RM.

Re: spi's dma mode receive data successfully but send data failed.

danielmartynek — Fri, 29 May 2020 15:50:03 GMT

Hi vanaua@163.com,

You didn't enabled peripheral request for DMA Ch1, you enabled DMA Ch0 only (SERQ).

Do you measure the correct pin?

In the project, you commented that MISO is PTD16 but it is PB4.

Do you use your own board or an EVB?

BR, Daniel