- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
When using negative edge registers or inverted clocks TimeQuest is incorrectly analyzing the timing.
module TEST(input clock_50, input in, output reg out);
reg tmp;
always @(posedge clock_50) tmp = in;
always @(negedge clock_50) out = tmp;
endmodule
from node: tmp, to node: out~reg0 setup: slack: 0.350, relationship: 0.500 hold: slack: 19.232, relationship: -19.500 With a 50Mhz clock the relationship should be 10.000, I don't understand why its giving the wrong value. The "-invert" option of create_generated_clock also gives the wrong value, however using "-phase 180" results in the expected relationship of 10.000, (half the clock period). Maybe this is a bug but I have failed to find any mention of this issue.
Link Copied
1 Reply
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Can you post screenshot of the waveforms from TimeQuest worst-case path report?

Reply
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page