xilinx and jtag

I have a jtag programmer with a 20pin idc connector.
Are these in general suitable for cplds/fpgas?

Also, I have the following test program. The program
is supposed to switch on  a led when the input is hi.
Is this program ok?

module modled(a1, b1);
input wire a1;
output wire b1;

assign b1=a1;

endmodule

On May 31, 10:16=A0am, <discussi...@fpga.usenet> wrote:
> I have a jtag programmer with a 20pin idc connector.
> Are these in general suitable for cplds/fpgas?
>
> Also, I have the following test program. The program
> is supposed to switch on =A0a led when the input is hi.
> Is this program ok?
>
> module modled(a1, b1);
> input wire a1;
> output wire b1;
>
> assign b1=3Da1;
>
> endmodule

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.

discussi...@fpga.usenet wrote:
> I have a jtag programmer with a 20pin idc connector.
> Are these in general suitable for cplds/fpgas?
>
> Also, I have the following test program. The program
> is supposed to switch on  a led when the input is hi.
> Is this program ok?
>
> module modled(a1, b1);
> input wire a1;
> output wire b1;
>
> assign b1=a1;
>
> endmodule

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

> 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.

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

>
> 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.

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

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

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?

discussions@fpga.usenet wrote:
  > 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.
>
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.

discussi...@fpga.usenet wrote:
<snip>
>
> 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.
<snip>

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

On Jun 3, 11:58 am, Ed McGettigan <ed.mcgetti...@xilinx.com> wrote:
> discussi...@fpga.usenet wrote:
>
>   > 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.
>
> 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.

Digilent (www.digilentinc.com) 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 (www.digilentinc.com) makes the Xilinx FPGA starter boards,
> and they have low-cost JTAG programming cables that work with Xilinx's
> iMPACT.

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.

Eric Smith <eric@brouhaha.com> wrote:

> Dave Pollum wrote;
> > Digilent (www.digilentinc.com) makes the Xilinx FPGA starter boards,
> > and they have low-cost JTAG programming cables that work with Xilinx's
> > iMPACT.

> 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 ----------

Uwe Bonnes wrote:
> Eric Smith <eric@brouhaha.com> wrote:
> 
> 
>>Dave Pollum wrote;
>>
>>>Digilent (www.digilentinc.com) makes the Xilinx FPGA starter boards,
>>>and they have low-cost JTAG programming cables that work with Xilinx's
>>>iMPACT.
> 
> 
>>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!

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