USB mounting in arm based lpc3250

[nightrapper]

Sir,

I would be trying hardware usb analyzer tool tomorrow and then would post the results.....

But i have some thing to clarify:

Our controller board is having OHCI host controller and the device we are attaching is EHCI device...are they compatible  and if not  is there any

way to connect the 2. Does this means we can connect only USB 1.1 to LPC32xx board in host mode and not usb 2.0?

In data sheet of lpc32xx it says USB OTG (On-The-Go) is a supplement to the USB 2.0 specification .Does this means that lpc32xx  support

USB 2.0 in OTG mode only?

[Jan Axelson]

Only hosts are EHCI. A device can be low, full, high speed or SuperSpeed. Some devices support two speeds.

The original OTG spec was a supplement to USB 2.0. The USB 3.0 spec now also includes OTG.

[Barry Twycross]

Being OHCI, you host would support full speed only. (As Jan mentiones, OHCI, and EHCI apply to hosts not devices.) Any high speed device should also support full speed. A device which wants to be high speed doesn't have to function at full speed, but its supposed to at least enumerate and tell you it has no function. I can't think of any high speed capable devices which don't actually have some function at full speed.

So basically you shouldn't have any problem, except things will be slow.

[nightrapper]

Sir,

I am attaching the snapshot and the file we collected while testing the USB on the ellisys protocol analyzer.Please find the attachment.
the resistor value we used for I2c pull up was 500ohm.






 

[attachment deleted by admin]

[Jan Axelson]

The analyzer shows incomplete IN transactions for the Read command and no data returned for Request Sense.

[nightrapper]

Sir,

Sorry for the late reply.
When I am testing the USB on the Ellisys protocol analyzer through CPU (Linux OS), It is executed successfully. I didn't get any errors. If the same thing done through the controller board (Having LPC3250 micro controller) I am getting errors. Why those errors are coming, Please kindly explain me.

And also I am attaching both snapshots while testing the USB through Linux & LPC3250 board.



[attachment deleted by admin]

[nightrapper]

Sir
you replied

"analyzer shows incomplete IN transactions for the Read command and no data returned for Request Sense"

What the reason for it.Can you just explain it little so that i can look into it?

Is this problem of USB i am testing or the pull up we are using in the circuit,we tried different combination of pull up but still the result is same?

[Jan Axelson]

Board.ufo shows a request for 512 bytes. The device returns 192 bytes and then apparently doesn't ACK further requests for data or return a STALL. The host gives up after 3 tries.

I think the host should still attempt to receive a CSW.

In the mass storage bulk only spec, see case 5 in "13 cases":

http://www.usb.org/developers/devclass_docs#approved

[nightrapper]

Sir,

The problem with ISP1301 still persist.

In new board we used micrel 2555 chip in place of isp 1301 and and in linux kernel we added the micrel patch file to linux kernel,the usb is working fine.

What i  found is that it may be because of the hardware problem in the board that the USB was not working,as in our new board some protection circuit is provided on the board as per datasheet.

As per to my satisfaction i am not sure where the problem was hardware or software. If i assume that it is software problem following thing i want to do please guide me wither i am write or wrong.

1.Write a device driver for the usb and test it

i am reading (Designing and Programming Devices and Embedded Hosts -Jan Axelson)  which would help me out to understand the USB  working procedure.
 
 

[Jan Axelson]

I don't know the reason for the problem you were seeing with the ISP1301. However, replacing it with a different chip makes sense since I believe the ISP1301 has been discontinued.