gnupic: Re: [gnupic] USB code, PICDEM FS USB and Linux
Subject:
RE: [gnupic] USB code, PICDEM FS USB and Linux
From:
"Bradley Minch" ####@####.####
Date:
3 Mar 2006 19:17:03 +0000
Message-Id: <280CB384F3297641AB0C74674FB22A7D0646541A@OLINEXVS01.olin.edu>
The host timing out waiting for the PIC to complete the status phase of
the control transfer, which for this type of request is a zero-length
data packet. That is what these four lines of code do (i.e., set the
byte count, BD0IBC, to zero, and transfer ownership of the EP0 IN buffer
back to the SIE.
Brad Minch.
-----Original Message-----
From: Ben Dugan ####@####.####
Sent: Fri 3/3/2006 1:14 PM
To: ####@####.####
Subject: Re: [gnupic] USB code, PICDEM FS USB and Linux
Alessandro,
I have been working more on sending to the picdem, using vendor
requests. Its working well for my purposes. The VendorRequests code you
put in usb-test.asm was very helpful getting me started on this.
I had been getting a timeout error from libusb when I sent vendor
requests to the board, even though the requests were working (that is, I
could get data to the board as I'd hoped.) I was thinking that the host
was waiting for some sort of acknowledgement, so I copied some lines
from elsewhere in the Minch code and it no longer times out. I'm noting
them here in case its of interest to you:
VendorRequests
banksel USB_buffer_data
movf USB_buffer_data+bRequest, W, BANKED
select
case 0x01
banksel demo_buffer
movf USB_buffer_data+wValue, W, BANKED
movwf demo_buffer+0, BANKED
movf USB_buffer_data+wValueHigh, W, BANKED
movwf demo_buffer+1, BANKED
movf USB_buffer_data+wIndex, W, BANKED
movwf demo_buffer+2, BANKED
movf USB_buffer_data+wIndexHigh, W,BANKED
movwf demo_buffer+3, BANKED
* movlw 0x0
* movwf BD0IBC, BANKED
* movlw 0xC8
* movwf BD0IST, BANKED
break
The four *'ed lines seem to eliminate the timeout error.
Ben
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