Hello Armin, thanks for the advice. To get the cable respoding i alreday needed to step down to 3Mhz, using 6Mhz always gave me an error like: Cable doesn't respond, TDO seems to be stuck at 1. I tried going down in steps till 100Khz, this didn't change the chain scan at all. I received all the time the same false device id.
Iam using a openocd usb cable from http://www.embedded-projects.net/index.php?page_id=256. The openocd usb design is around for some time, so i suspect the support in openocd and urjtag is quite mature. Talking about electrical issue, since iam using the openocd usb cable on my Digilent Nexys2 board with has also a builtin jtag which is Usbblaster compatible, maybe the builtin jtag interface interferes with the external interface. If would attach a LA the external jtag pins, how would i see that i get cross talk from that internal jtag device? --David On 2010-03-21, at 7:45 PM, Arnim Läuger wrote: > Hi David, > >> iam trying to use an Otenocd USB cable to upload a bitstream to a spartan3e >> on a Digilent Nexsy2 board. Seems that urjtag can't identify the fpga >> properly. >> >> jtag> cable USB-TO-JTAG-IF >> Connected to libftd2xx driver. >> jtag> frequency 3000000 >> Setting TCK frequency to 3000000 Hz > > I'd suspect an electrical issue, mismatched levels or cross-talk. > You've already decreased the frequency - does it get any better when > decrease even more? > > Cheers > Arnim > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ UrJTAG-development mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/urjtag-development
