2. 技术支持
  3. AR# 4974: 4.1i 4000E MAP - MAP incorrectly trims OUTFFTs that are permanently active.

AR# 4974

4.1i 4000E MAP - MAP incorrectly trims OUTFFTs that are permanently active.

描述

Keywords: XNF, OUTFFT trimmed.

Urgency: Standard

General Description:
Pins attached to an OUTFFT with the T tied low (on) in an .xnf file are being trimmed. I cannot simply use OUTFFs, because the design may really be toggling T of OUTFFT.

解决方案

You can work around this problem by placing a "nomerge" attribute on the TBUF control net. This can be done in the .ucf file:

NET "netname" KEEP ;
AR# 4974
日期 08/20/2003
状态 Archive
Type 综合文章