S32K324 DMA initialzation and use

[DY_Liu]

Hi team.

How should I use DMA?

The DMA I configured was debugged normally, but the full speed operation was abnormal.

basic register to configurate.

For example:

1) initialze uart

2) enable uart dma request (key point)

3) config DMAMUX

4) config DMA

5) enable DMA (key point)

......

Thanks

[Julián_AragónM]

Hi @DY_Liu

Chapter 14.4 of the S32K3xx MCU Family - Reference Manual provides instructions for initializing the DMA channel MUX.

You can also take a look into this DMA with UART example with the S32K344 in this community post:

• Solved: S32K344 UART DMA example - NXP Community

I hope you find this helpful!

Best regards,
Julián.

[DY_Liu]

Hi.@Julián_AragónM

Thank you for you help.

But I have a problem, The first call must have a breakpoint, otherwise it will fail.

Type 1:

DY_Liu_0-1704258544821.png

DY_Liu_1-1704258561587.png

Type 2:

DY_Liu_2-1704258734546.png

DY_Liu_3-1704258752437.png

DY_Liu_4-1704258769765.png

api:

DY_Liu_5-1704258799988.png

DY_Liu_6-1704258829002.png

DY_Liu_7-1704258843676.png

[Julián_AragónM]

Hi @DY_Liu,

Could you give us more details about the error? What is the problem if the delay is not set? This is so we can reproduce the example to see if the behavior persists.

Best regards,
Julián.

[DY_Liu · Accepted solution]

Hi. Julián_AragónM
I found the reason, Cache must be invalidated.

thanks!