procedure of USB host dma transfer

Sheng Hu

Other Parts Discussed in Thread: TMS320C6748

Assume I have submitted the HPD to queue 16, do I need to set TXPKTRDY bit in TXCSR in order to start a bulk out transfer?

Can you give me a to-do list for a bulk out transfer. The following are what I am trying to do.

1) set up a HPD with a data buffer, link it to compQueue 24

2) set queue[16].CTRLD

3) After 2), the 16th bit of PENDING0 is set.

4) set FLUSHFIFO & CLRDATATOG & MODE & DMAEN & DMAMODE

5) Reset FRCDATATOG & AUTOSET in ep1 TXCSR

6) After reset AUTOSET, the OMAP should send data in queue 16 out

7) After 6), the 24th bit of PENDING0 is set.

8) Check TXCSR to see what stats is returned from the usb device. ACK or STALL or NAK

Can you help to clarify these? And For a BULK IN transfer, after I submit the descriptor to the queue 0 with complete queue 26, do I need to set HOST_RXCSR's REQPKT to start a IN transfer?

Thanks

Sheng

over 14 years ago

0 twicave Feng over 14 years ago

Intellectual 850 points

I just checked my code based TMS320C6748.

when you worked in usb host mode.

when you want epout, you just need emit a Send-out-queue. doesn't need to operate the raw-register.(because when dma push a frame into FIFO, the TxPktReady bit of TXCSR is auto set.)

but when you epin, you need manually set RxCSR to send out a "IN TOKEN".

operate usb peripheral manully is very boring. TI suggest you use usb-stack developed by themselves.

It took me 6 months to complete both host and peripheral mode of USB.

any way, good luck.

0 twicave Feng over 14 years ago in reply to twicave Feng

Intellectual 850 points

In usb2.0 peripheral manual there are some example code, you should take a look.

0 Sheng Hu over 14 years ago in reply to twicave Feng

Prodigy 205 points

thanks for your help and kindness.

I have made the functionality of dma transfer work according to your advice.

I am wondering whether their usb stack is open-source or it is a bin lib?

Cheers,

sheng

0 twicave Feng over 14 years ago in reply to Sheng Hu

Intellectual 850 points

That product from TI is named "BIOSUSB".

as it's name shows, It's a package belong to DSP/BIOS(DSP/BIOS5.x).

as I know, It just works on chips: 6747, 6748, omap137,omap138.

there are some discussions in BIOS forum.

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procedure of USB host dma transfer