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Re: [Discuss-gnuradio] SSRP 7/13
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] SSRP 7/13 |
Date: |
Sat, 17 Jul 2004 09:49:36 -0700 |
User-agent: |
Mutt/1.4.1i |
On Tue, Jul 13, 2004 at 07:40:22PM -0500, David Carr wrote:
> Hi all,
>
> The IO test board is complete and tested. Pictures are in the I/O
> test board section at: oscar.dcarr.org/ssrp/
> Secondly, I've succeeded in moving ~16MB/s from the test board to my
> laptop using some simple bulk transfer firmware. This is fast enough
> but it seems a little slow considering I have the 82801DB (ICH4)
> chipset. I used 512 byte packets to fx2_programmer reading 4096 byte
> chunks. Any suggestions?
Use the fusb*.{h,cc} and test_fusb.c code out of the usrp tarball.
Using the standard libusb interface under linux xfers a maximum of 4kB
across the user/kernel boundary at a time, regardless of the arguments
that you pass, and the calls block until the requests complete. The
"fast usb" code (fusb*.{h,cc}) uses the usbfs interface to submit
multiple USB request blocks asynchronously. This allows us to sustain
over 32MB/sec.
> Does anyone have a vendor for
> these or similar? I'm also willing to try a photoresist PCB
> technique, is 8mil resolution achieveable?
There are a ton of quick turn proto shops that will build you a few
boards for under $100. You upload your gerbers and they ship you
boards in a few days. Their processes typically handle 7mil space and
trace. Here are a few starting points.
http://www.google.com/search?q=pcb%20prototypes
http://www.pcbexpress.com
https://www.2justforyou.com/NASApp/sierraproject/jsp/tabs_welcome_home_.jsp
Eric