Using Impact 12.xthrough 14.x, I receive an IDCODE error when I try and initialize my chain. What is the reason for this?
If you happen to have the older UMC 18V00 PROM, then you have to modify the IDCODE value in the BSDL file.
If you refer to the BSDL file, you will see this note.:
-- Revisions: -- 12/17/09 - Removed support for UMC XC18V00, indicated by IDCODE=0; -- This BSDL supports only the STMicro XC18V00, IDCODE=1.
To work around this issue, you will have to hand modify the IDCODE and change bit 16 to a '0' or to a Don't Care bit 'X' if you have both UMC and STMicro parts. This will now pass the Impact IDCODE check.