xilinx and jtag

Yes, the jtag programmer is suitable for cplds/fpgas from a variety of manufacturers. JTAG is a standard and as such will be compatible. As for your program, try simulating and seeing what you get.

Keep in mind the 20 pin header may be rearranged from what your cpld/ fpga board expects; there is no header standard used throughout the industry. Also please make sure your JTAG voltages are compatible. Does your jtag programmer include your xilinx devices as a target? I end up just using the Xilinx USB Platform Cable to program my chips directly from the Xilinx utilities when I'm doing iterative design. A different JTAG programmer will probably need a generic, compatible file format.

The Verilog module you included is one step in your journey. You may find a high on the input turns off the LED by driving the cathode high, depending on your board (active low logic). You still need to compile the code, assign pins, place & route the design, and generate a programming file.

You have all that down? It should be covered pretty well in the documantation available to you.

Welcome to the fun,

- John_H

I had to remove the idc plug to make direct connection to vdd/vss/tdo/tdi/tck/tms but still webpack impact will not recognise the cable. It seems to me some jtag programmers are not compatible with xilinx.

I have the jtag schematic from xilinx Title: jtag/parallel download cable comments: 0380507

10 july 1996 ver 2

According to this schematic D6/Busy/Pe (pins 8/11/12) should be connected together, yet by looking at this jtag of mine I don't see this at all.

I tried to build an unbuffered programmer for a schematic I found on wikipedia; this had better results, but still not working as I think it should; it can erase the chip, test for erased chip, program, but the check sum always comes back wrong, and the led doesn't come on either. more below

Yes, done all that, and yes - I did insert the led the right way round.

Yes, all the documentation is good and it is fun, but it will be more fun if my jtag will start working, at least returning correct checksums?

snipped-for-privacy@fpga.usenet wrote: > I had to remove the idc plug to make direct connection to

The Xilinx tools (iMPACT, ChipScope) only work with cables that they have been designed for, they will not work with any random JTAG cable.

Ed McGettigan

-- Xilinx Inc.

Virtually all jtag programmers are not compatible with the Impact tool. Your jtag programmer SOFTWARE may be compatible with Xilinx programming files, however.

Or just spend $150 on a very good Xilinx USB Plaform Programmer cable.

- John_H

vdd/vss/tdo/tdi/tck/tms but still webpack impact will not

Digilent

makes the Xilinx FPGA starter boards, and they have low-cost JTAG programming cables that work with Xilinx's iMPACT. HTH

-Dave Pollum

Dave Pollum wrote;

Digilent's parallel cable works, because it's a clone of the Xilinx Parallel Cable III.

Digilent's USB cable does NOT work with Impact, ChipScope, etc.

It's a pity, that Xilinx doesn't open their JTAG Api. Many FPGA boards have a USB Chip like the FT2232 or FX2 to do data communication. JTAG protocoll could easily be handled by them too. But to use Impact and or Chipscope, you have to provide an extra JTAG input for a XILINX-known cable adapter.

Silly!

--
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

Weren't there rumblings from within the depths of Xilinx about making that portion of the tool chain open-source ?. Makes sense, given the very wide range of programming combinations that exist, and in many cases Xilinx is NOT the only device.

Is the person handling that still there ?

-jg