There are different jtag pin configuration/function on most vendors. For example the Xilinx jtag is different from the Altera and (for example) both of them does not work for National ethernet PHY chip JTAG. Also I will use with precautions the jtag chaining between various families of FPGA or FPGA and DSP. best wishes, Vasile On 8/16/07, Bob Blick wrote: > Hi Forrest, > > Once I tried to follow the same path. I gave up, and now I have three > different JTAG programmers. All is well. > > Cheerful regards, > > Bob > > > Forrest W Christian wrote: > > I'm in need of a JTAG interface cable for a project I'm working on. I'm > > trying to figure out the best way to proceed. > > > > In short, it looks like although the JTAG interface on the > > system-under-test-or-programming side is fairly standardized, the > > interface on the PC is anything but. It looks like to program a device > > via JTAG, you need an appropriate pice of software on the PC which knows > > how to drive the JTAG for that device to do the programming. It also > > looks like each of these software packages only support certain cables, > > and which ones don't appear to be well documented at all. > > > > For the immediate project I could build a cable, but would prefer to > > find a solution which will work for almost anything I need it for JTAG > > wise since it seems that there are getting to be more and more projects > > which need a JTAG "programmer" for some part of it. In fact, right now, > > I have two projects to work on - the critical one, and another which has > > been waiting in the wings. > > > > For those of you which use JTAG, which interface cable would you > > recommend I build or buy for the broadest support of devices? > > > > -forrest > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist