Timing Closure Inquiry / Failure
6524 - Lattice Diamond: How do i allow the tool to analyze the CDC from my design and view paths on Trace reports?
Users must add in a CLKSKEWDIFF constraint in order for the tool to analyze the different clock domains. Without this constraint, the tool will not report/analyze any CDC from the trace reports.
7037 - All Nexus / Radiant 2023.1 or earlier: How are the clock-to-out max and clock-to-out min values on the I/O Timing Analysis report calculated?
Clock-to-out max corresponds to the arrival time of the data of the external timing path when setup time is analyzed. Clock-to-out min corresponds to the arrival time of the data of the external timing path when hold time is analyzed. If there are ...
6507 - Lattice Diamond: Why are there no paths analyzed for MAXDELAY constraint. How to use MAXDELAY constraints?
The MAXDELAY constraint used in the design might not be connected, or they are on a different clock. Diamond STA won't analysis on different clock domains unless they are related by clkskewdiff For Example, if two cells are in different clock ...
7021 - All Nexus / Radiant 2023.1 and older: How can the user calculate the Clock-To-Out (min and max) values and Input setup/hold values of the I/O Timing Analysis report?
The Clock-to-Out max value is the setup analysis' arrival time of data with the output port's external timing path. The Clock-To-Out min value is the hold analysis' arrival time of data with the output port's external timing path. By default, timing ...
7000 - Lattice Radiant: Why does the constraint coverage did not improve after using set_false_path constraint?
By Default, set_false_paths does not improve constraint coverage, however For Radiant 2023.1 or later, the user can use the Timing Command Line Option "-false_covers" to add in the false paths to the timing coverage. This can be applied on the ...
6470 - All Nexus / Radiant version 2023.1 or earlier: Is it correct to think that STA is performed under worst-case conditions for both setup/hold for Nexus Devices?
Radiant timing analysis is performed under worst-case conditions for both setup/hold. As an example, consider the Nexus devices. By default, hold analysis is performed using the ‘m’ speed grade which represents the highest performance grade using the ...
5913 - Lattice Radiant: Why Fmax is reduced after encrypting a source file using IEEE-1735 standard?
This is not uncommon when using encrypted files. Commonly, when source files are encrypted, the same result (or better) cannot be expected from design tools (Lattice tools or any other tools in the EDA industry). When modules/files are encrypted, we ...
6947 - Radiant: How can users reduce the high delay value on the output pad?
To reduce the delay on the output pad, users can use the FAST slew rate option on the Device Constraints Editor instead of the SLOW (default) or MED value.
6945 - Radiant: How does the user set constraints for a MII interface?
1. First step is to check the specs of the MII PHY. As an example, see analysis of the specs MII PHY together with what constraint would used the spec. ...