General Technical Discussion

[mehul1123]

I have a spartan 3 xc3s400 FPGA as well as xc9572 CPLD boards(meant for education purpose).
I am using windows xp.
I am using Xilinx ISE 9.2i

When I press initialize chain button in impact tool some popup 
question says=> 
"There are many unknown devices being detected. Press yes to continue 
or Press NO to stop"
If I say yes. PC become non responsive
If I say no it gives an error => ERROR: IMPACT:585 A problem may exist 
in the hardware configuration. Check that the cable, scan chain, ............

[gszakacs]

This error generally means that there is a break in the JTAG chain somewhere causing

the TDO to continuously shift out garbage - interpreted as "many unknown devices."

The problem can be in the cable or on the board.  Usually the break is in the data chain

TDI to TDO through the various chips, however it may be possible for a misconnected

TMS or TCK signal to cause this, too.

Is this board your own design or is it a commercially available eval board or kit?

-- Gabor

[mehul1123]

it is commercial board.

 supplied by a educational kit provider.

as far as i know no one has used it till date.

with the same JTAG connector i connected another board and it's working fine..

[eteam00]

Have you contacted the supplier or manufacturer of the kit for assistance?  The problem may be as simple as a missing jumper.

-- Bob Elkind