S32KのトピックRe: Send data with flexI2S via continious DMA. (S32K116)

Send data with flexI2S via continious DMA. (S32K116)

Furkan07 — Fri, 24 Mar 2023 15:02:17 GMT

Hi, I trying data send with dma as a scatter/gather. My purpose is to send data(for example a 120-byte array) with flexI2S.
I want dma to send the same array again when 120 bytes are finished automatically without any triggering in the loop while.

I reviewed the "edma_transfer_s32k146" project on S32DS. The project was not configured to send data from the flex module.
I cannot do what I am trying to do by setting the scatterGatherEnable variable to true and giving the scatterGatherNextDescAddr the address of the directory.

What do you think is missing in this program for what I want to do? (Does S32K116 processor have any restrictions to do this? Do you have a sample project that does this? It doesn't matter if it's FlexI2C, FlexSPI or something.)

In addition, I added configuration to flex module, like this:

const flexio_i2s_master_user_config_t flexio_i2s1_MasterConfig0 = {

.driverType = FLEXIO_DRIVER_TYPE_DMA,

.baudRate = 725000UL,

.bitsWidth = 8U,

.txPin = 4U, //PTD2

.rxPin = 5U, //PTD3

.sckPin = 0U, //PTD0

.wsPin = 1U, //PTD1

.callback = NULL,

.callbackParam = NULL,

.rxDMAChannel = 1U,

.txDMAChannel = 0U

};

Also, if I send the data with the "FLEXIO_I2S_DRV_MasterSendData" function after checking via FLEXIO_I2S_DRV_MasterGetStatus() in the while loop, the flex module sends the data successfully. But what I need is to create a seamless I2S clock signal.

Re: Send data with flexI2S via continious DMA. (S32K116)

danielmartynek — Thu, 30 Mar 2023 14:07:40 GMT

Hi @Furkan07,

Although the FlexIO SDK driver does not support it, the DMA channel can be triggered again at the end of the Major loop.

TCDn_CSR[MAJORLINKCH] can be set the n channel.

Regards,

Daniel

Re: Send data with flexI2S via continious DMA. (S32K116)

Furkan07 — Fri, 07 Apr 2023 14:31:51 GMT

Yes, you are right. I was able re-trigger the DMA channel when the DMA data send finished for creating a continuous DMA transmission. Result; (blue: clk, yellow: data)

But it took some time to figure out how to do it. Even the simple process of sending a string continuously requires reading quite a few resources on the minor loop and the major loop. The fact that NXP doesn't do it as simply as in CUBE MX is challenging for NXP beginners.

@danielmartynek, Thank you for the reply.