FPGA-FAQ    0001

JTAG Configuration

Vendor Xilinx
FAQ Entry Author Evan
FAQ Entry Editor Philip Freidin
FAQ Entry Date 02/18/2001

Q. Help! I can't configure through JTAG.


Evan :
Q1: JTAG Programmer fails with a message about checking power supplies
and connections. What's wrong?

A1: This is a well known software bug. The error message is incorrect;
it should read: "this software has now expired; download today's
version. See FAQ A2 for further details."

Q2: I didn't get that error message, but I still can't configure.
What's wrong?

A2: Your software is out of date. It doesn't matter if you downloaded
it only 2 weeks ago, or if your hardware's 10 years old, your software
is certainly out of date. Get **todays** 10Mbyte download.

Q3: Ok, that didn't fix it. What now?

A3: Try the following:
(a) pull out all cables
(b) plug in all cables
(c) power everything down
(d) power everything up
(e) download a circuit diagram for the parallel III cable. Take the
top off, peer around, put the top back on again.
(f) identify all powered components and cables in your system. Create
a matrix which defines all possible sequences for removing and
re-applying power, together with all combinations for cable connection
and disconnection. Execute exhaustively.
(g) Repeat steps (a) through (f), in a random order, until you can't
take any more.

Q4: Ok, that didn't work either. What now?

A4: If you're one of those saddos who posts to NGs, then mail to
comp.arch.fpga complaining that JTAG programming doesn't work. Please
use the subject line "Help! I can't configure through JTAG" to keep
down the traffic. You will be referred to a FAQ entry entitled "Help!
I can't configure through JTAG". When you get down to Q4, please do
*not* repeat this step.

Q5: Ok, that didn't help. What now?

A5: Forget it; go home. It'll work in the morning.