Answers Database
XPLA Professional: Functional simulation works but timing simulation yields unknown outputs
Record #7810
Product Family: Software
Product Line: CoolRunner
Product Part: XPLA Simulator
Product Version: 3.31
Problem Title:
XPLA Professional: Functional simulation works but timing simulation yields unknown outputs
Problem Description:
Urgency: Standard
General Description: Functional simulation work as expected,
yet when a timing simulation is done using the same simulation
control language (SCL) file, all of the outputs remain in an
unknown state.
Solution 1:
If the global tri-state (GTS) signal is used in the design, then this
signal must be added to the timing simulation. The name of the
signal in the simulator should be RESERVED_DUT. Adding this
signal and setting it to the correct logic state will release the global
tri-state line, and allow the outputs to function as expected.
Because this signal is not available until the design has been fit
into the desired architecture, this signal is not available to the
functional simulator. Therefore, if the GTS is used, this signal must
be manually added to the timing simulation.
End of Record #7810 - Last Modified: 10/14/99 18:12 |
