AR# 11917: 4.1i Virtex-II MAP - IOB (programmable) delay is incorrectly turned "On" for an IOB with a DCM-based clock.
AR# 11917
4.1i Virtex-II MAP - IOB (programmable) delay is incorrectly turned "On" for an IOB with a DCM-based clock.
描述
Keywords: Virtex-II, IOB, programmable, delay, on, default, DCM
Urgency: Standard
General Description: In a Virtex-II design, the IOB delay is turned "On" by default in an IOB where a flip-flop is clocked by a DCM-based clock. (This IOB delay should not be on in this case.)
解决方案
To work around this problem, use the NODELAY attribute.
This can be done in the UCF or NCF files by using the following format: