怎么设置和重置XIL_TIMING_ALLOW_IMPOSSIBLE

喜
我在Windows XP上安装了xilinx ISE 10.1。
我在地图中遇到了一些时间问题，所以我在ISE的tcl窗口中将xil_timing_allow_impossible设置为1。
地图经历了。
但是，现在当我将xil_timing_allow_impossible重置为0时，即使我在后映射时序报告中可以看到一些时序违规，地图仍然成功完成。
我用来设置env变量的语法是 -
％set env（XIL_TIMING_ALLOW_IMPOSSIBLE）1
1
％echo $ env（XIL_TIMING_ALLOW_IMPOSSIBLE）
1
我用来重置env变量的语法是 -
％set env（XIL_TIMING_ALLOW_IMPOSSIBLE）0
0
％echo $ env（XIL_TIMING_ALLOW_IMPOSSIBLE）0
所以我甚至设置/重置这个环境。
变量合适吗？
或者我在语法中遗漏了什么？
如果我正确地重置变量，那么即使有时间违规，下一次地图也会如何通过。
帮帮我！
ž。



以下为原文

hi,

i have xilinx ISE 10.1 on windows XP.

i had some timing issues in map so I set the xil_timing_allow_impossible to 1 in the tcl window in ISE.

the map went through.

however, now when I reset the xil_timing_allow_impossible back to 0, map is still completing successfully, even though I can see some timing violations in the post map timing report.

the syntax I used to set the  env variable is -
% set env(XIL_TIMING_ALLOW_IMPOSSIBLE) 1
1
% echo $env(XIL_TIMING_ALLOW_IMPOSSIBLE)
1

the syntax I used to reset the env variable is -
% set env(XIL_TIMING_ALLOW_IMPOSSIBLE) 0
0
% echo $env(XIL_TIMING_ALLOW_IMPOSSIBLE)
0

So am I even setting/resetting this env. variable properly? or am I missing something in the syntax?

And if I am resetting the variable properly, how come map goes through next time around, even when there are timing violations.

Help!

z.