topic Re: Receive sai multichannel data into multiple buffs using sdma in i.MX Processors

Receive sai multichannel data into multiple buffs using sdma

tongt — Fri, 17 May 2024 06:53:27 GMT

使用sdma接收sai多通道数据到多个buff中

Receive sai multichannel data into multiple buffs using sdma

在使用sai及sdma接收数据的时候，如果使用multififo等机制，接收到的数据会在一个buff中，能不能使用sdma的多通道功能，使接收到的数据按照通道分散到各执的buff中？

When using sai and sdma to receive data, if you use such as multififo, the received data will be in a buff, can you use the multi-channel function of sdma so that the received data is dispersed according to the channel in the buff of each execution?

以上图为例子，第一组4字节为第一个通道，连续的第二组4字节为第二个通道，总共4个通道，实际使用的时候需要对某一个通道的数据进行拷贝，拷贝出一个完整通道的数据
The above figure as an example, the first group of 4 bytes for the first channel, the second consecutive group of 4 bytes for the second channel, a total of 4 channels, the actual use of the time you need to copy the data of a channel, copy out a complete channel data

我尝试使用如下代码，但是回调函数总是不能被调用

I tried to use the following code, but the callback function always fails to be called

这种方案有没有问题，能不能实现，如果要实现需要关注哪些呢？

Are there any problems with this option, can it be achieved, and what needs to be focused on if it is to be achieved?

Re: Receive sai multichannel data into multiple buffs using sdma

Zhiming_Liu — Mon, 20 May 2024 10:59:30 GMT

Hi @tongt

你用的是哪颗芯片？

Re: Receive sai multichannel data into multiple buffs using sdma

tongt — Tue, 21 May 2024 02:47:59 GMT

imx8mp

Re: Receive sai multichannel data into multiple buffs using sdma

tongt — Tue, 21 May 2024 03:22:51 GMT

另外我还修改了 SAI_TransferRxCreateHandleSDMA以及

/*<! Private handle only used for internally. */

static sai_sdma_private_handle_t s_sdmaPrivateHandle[ARRAY_SIZE(s_saiBases)][16];

@Zhiming_Liu 感谢回复

Re: Receive sai multichannel data into multiple buffs using sdma

Zhiming_Liu — Tue, 21 May 2024 06:59:34 GMT

Hi @tongt

你的这个想法已经在SDK里集成了，但是用法不对。smda script里有针对SAI multi-fifo的脚本，详细参数请看手册的 A.3.2.8 mcu_2_sai

SDK里的SAI_TransferSendSDMA API也支持script里的这个功能，如果配置的通道数大于1，SAI_TransferSendSDMA 里会使用milti-fifo这个功能读取数据，然后返回第一个buffer，对于其余的buffer，是在这个buffer基础上＋offset（默认是4U）。callback应该是一个就行，然后指定通道的时候用或逻辑试试。然后设置saiConfig里的channelNums和channelMask

Re: Receive sai multichannel data into multiple buffs using sdma

tongt — Tue, 28 May 2024 08:03:02 GMT

@Zhiming_Liu 下午好

目前接收是使用了multi fifo的。offset的类型为uint8_t，也就是最大为255，如果需要buff的偏移更大，有没有办法呢（目前每次接收64K数据，包含4个通道，每4个字节交错），如果不使用offset，如之前说的，4个通道能不能对应到sdma的4个通道上，这4个sdma的通道对应4个不同的buff地址，能不能实现呢

Re: Receive sai multichannel data into multiple buffs using sdma

Zhiming_Liu — Thu, 30 May 2024 01:40:43 GMT

在未对SDK大幅改动的情况下，不行，而且目前的sdma脚本只支持交错存储，不支持自定义的多个buffer地址。

Re: Receive sai multichannel data into multiple buffs using sdma

tongt — Thu, 30 May 2024 05:45:47 GMT

谢谢