how to choose DMA request source?

[zhangk]

hello everybody,Now,I am using this board to test uart，My configuration is :

PORT: pc8--TX  PC9--rx  LinFlexD_2

Baud rate: 38400

DMA Channel: 0

 I want to get transmitted data through DMA to UART on terminal,so I have to config DMAMUX, which DMA request source should I choose?（this is my configuration）

zhangk_1-1683169606916.png

zhangk_2-1683169654404.png

look,this my board，The serial port and openSDA are the same port，Is it feasible to configure LinFlexD_2 to use DMA?

zhangk_0-1683169271973.png

this is my  peri_clock_gating function

zhangk_3-1683169822416.png

[PetrS]

Hi,

only LINFlexD_0 and LINFlexD_1 support DMA

PetrS_0-1683181109916.png

BR, Petr

[zhangk]

Oh!，thank you so much,I have decided to change the serial port LinFlex， If I use LinFlexD_0 or LinFlexD_1,which DMA request source should I choose?I looked at some examples, such as the MPC5775K, which use source 14, but I didn't find them in the manual

zhangk_0-1683182016262.png

zhangk_1-1683182173180.png

[PetrS · Accepted solution]

HI,

as you can see from table 71-1 you posted, source number for DMAMUX setting is 29 in case of LINFlexD TX DMA request. For LINFlexD_0 you configure DMAMUX_0, for LINFlexD_1 configure DMAMUX_1.
This device includes two DMA request MUXes that allows up to 32 DMA request signals to be mapped to the first 16 DMA channels [DMA_CH0 - DMA_CH15] for DMACHMUX_0 and the last 16 DMA channels [DMA_CH16 - DMA_CH31] for DMACHMUX_1.

BR, Petr

[zhangk]

Thanks! I have changed the serial port configuration to LinflexD_1，But now there is a new problem，Every time I go into debugging，then  click pause，It will be like this：

zhangk_0-1683193879473.png

I think it's my DMA configuration that is wrong，this is my dma configuration

zhangk_1-1683194033421.png

and this is AIP_INIT:

zhangk_2-1683194134255.png

zhangk_3-1683194167886.png

this is uart init

zhangk_4-1683194288356.png

Finally, I configured peri_clock_gating

zhangk_5-1683194379472.png

The main function is like this：

zhangk_6-1683194446865.png

Am I missing any configuration?

[PetrS]

Hi,

the UARTCR is not properly configured, you have several writes to register.

BR, Petr

[zhangk]

Thank you so much!，I've solved it today，I referred to this this https://community.nxp.com/t5/MPC5xxx/MPC5746C-LINFlexD-1-DMARXE-DMATXE/m-p/879852