topic USB isochronous transfer queries in i.MX Processors

USB isochronous transfer queries

binaeksarkar — Mon, 06 Apr 2015 10:17:49 GMT

Hi,

I have some queries regarding usb isochronous endpoint operation for device controller. I am referring to the document "IMX6DQRM-Rev1.pdf" section 65.4.5.

1. During an isochronous in transfer, does Dqh contain only one Dtd which has only one Iso (micro)frame or does Dqh contain one or multiple linked Dtds which has an input buffer filled with many iso frame/microframe? If multiple then how does device controller identify (micro)frame boundaries in dtds?

2. Is there any DMA operation involved while moving data between DTD and TX/RX FIFO? If DMA is present then what is the DMA restriction of buffer size and start address alignment?

Thanks

Barindam

Re: USB isochronous transfer queries

CarlosCasillas — Thu, 09 Apr 2015 23:38:53 GMT

Hi Barindam,

Could you please specify if you still having these queries or you are already on the stage mentioned on your other thread?

Additionally, you could take a look to application note AN4589 “Configuring USB on i.MX 6 Series Processors”, which provides useful information regarding USB on i.MX6 series.

Hope this will be useful for you.
Best regards!
/Carlos

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