6747 usb interrupt seemed having problem

twicave Feng

Intellectual 850 points

c6747. usb worked in Bulk protocol.

the protocol is very simply, It can divided into 3 steps:

1) OUT a package (CBW ctrol block. which inform device send some data up, or put some data down).

2) IN/OUT several package. in my case, always 8 package(64 bytes per package, 64 is device ep's maxp)

3) IN a package (CSW)

I set Interval of epOut or epIn which equal = 2, so if op timeout, I can capture this event.

Here is the experiment result:

Several times when RECV package from device, epOut timeout event is triggered. But at this moment, I have move into Step2(that means the Transmit Queue Event has happed, And I am trying to recv sth, now).

why?

over 16 years ago

0 swami over 16 years ago

TI__Expert 7435 points

Feng,

It seems that you are trying to develop a MSC application. MSC is already supported ove BIOSUSB stack that you can use readily. Can you try using the BIOSUSB stack?

regards

swami

0 twicave Feng over 16 years ago in reply to swami

Intellectual 850 points

hi, swami,

My product is time critical.

so It seemed I can't introduce BIOS into it.

thanks a lot.

0 twicave Feng over 16 years ago

Intellectual 850 points

[ continue... ]

When epOut INT event happed.

USB0_HOST_TXCSR = 0x1483 or 0x1583. It indicated that is an "ep timeout event".

I tryed to clear all pending Read and Write op and re-send command to device.

but program looped at here:

while( USB0_HOST_TXCSR &(1<<0) ) USB0_HOST_TXCSR |= (1<<3);

so what happens? why I can't flush Tx buffer?

0 swami over 16 years ago in reply to twicave Feng

TI__Expert 7435 points

Feng.

I believe BIOS is a RTOS and you would get all the needed support and ready built driver and apps.

regards

swami

0 twicave Feng over 16 years ago in reply to swami

Intellectual 850 points

I still want to know detail.

about my question, here is my guess:

when I send package by USB(in DMA mode),

when CPPI DMA have send package out, It immediately generate a complete queue without judging whether device ACK or NAK, Is that right?

If It is right. How can I judge the transmit operation is completed?

0 swami over 16 years ago in reply to twicave Feng

TI__Expert 7435 points

Pl. refer to the Linux USB driver for the implementation detail.

CPPI DMA raises Tx completion interrupt once the data has been moved into the Tx Fifo. It might take some more time for the packet to actually be transmitted on the bus and hence the toggle to get updated with the correct value.

You would have to poll TXCSR to ensure that the data has indeed left the fifo and then save the toggle information.

regards

swami

0 twicave Feng over 16 years ago in reply to swami

Intellectual 850 points

thanks god. thanks swami.

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6747 usb interrupt seemed having problem