Kinetis Microcontrollers中的主题 Re: Two induvidual I2S Streams on K20 72mhz

Two induvidual I2S Streams on K20 72mhz

tobias_strate — Wed, 24 May 2017 07:22:44 GMT

Hello
i have moderate amount of Experience with Kinetis Studio and processor expert.
I am working on a project which contains an I2S to S/PDIF Codec and an audio codec. I will need to send an receive to both of these simultaneously.

From the datasheet of the K20 processor i see that it should be able to handle two I2S streams yet i cannot find how to set it up, i know the DMA needs to move the data back and forth but which registers do i move the data from and to?

I think i am quite lost on this one, hope someone can throw me a rope.

Best Regards

Tobias T. Strate

Re: Two induvidual I2S Streams on K20 72mhz

jingpan — Fri, 16 Jun 2017 10:27:10 GMT

Hi Tobias,

If you want to call a DMA transfer when I2S received data, the I2S Rx is the DMA source. Conversely, if you want to call a DMA transfer when I2S need more data, the I2S Tx is the DMA source.There is a DMA request source table in K20P100M72SF1RM.pdf page 80. You can set corresponding number to DMAMUX's register.

There are some resource you can refer to. If you have download K20 SDK package, please refer to SDK_2.2_MK20DN512xxx10\boards\twrk60d100m\driver_examples\sai\edma_transfer.

Although it works in SAI mode, the dma setting is useful.

You can also refer to AN4800 which you can find on NXP website.

Hope my suggesting will be useful to you

Regards

Re: Two induvidual I2S Streams on K20 72mhz

tobias_strate — Fri, 16 Jun 2017 10:34:47 GMT

Thanks alot.
i will take a look at it.

Re: Two induvidual I2S Streams on K20 72mhz

tobias_strate — Wed, 21 Jun 2017 07:26:05 GMT

i have tried making a setup purely with the Init components, but it is not working, it seems to be the DMA and I2S interrupt which is not working. i have added the PE_ISR(DMA_interrupt) to Events.C. Yet it never seems to be called,