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MPC5746C DSPI DMA configure failure

Question asked by kupa harry on May 10, 2019
Latest reply on May 11, 2019 by kupa harry

I am using DSPI_1 with DMA to transmit and receive data,here is my configuration for dspi ,dma module.

I want to transfer eitght bytes through dspi with dma automatically.I triggered the DMA channel 0 through  

DMA.TCD[0].CSR.B.START bit to start dspi transmission . But it failed, DSPI_1 just transmited 4 bytes.and 

the receive buffer doesn't have received four bytes. I think the DMA0 just complete one minor loop, TFFF flag and CMDFFF flag of DSPI_SR don't trigger the DMA to start next minor loop. So I checked the DMAMUX module, the configuration is true that source of DMA for DSPI1_TX is 21, the source of DMA for DSPI1_RX is 22.I wondor what's wrong with my code.

Next,I tried to delete the DMAMUX configuration,and the result is the same, DSPI_1 just transmits four bytes .

Help me,  i am a beginner for DMA, and i just wonder the problem is DMAMUX configuration,but I can't find the specific mistakes I made.