Figure 1. Report Datasheet: Groups Tab
The Groups tab defines custom port groups for skew analysis. If you do not define any groups, the timer automatically identifies output port groups based on the launching clock and calculates skew from that clock.
The Groups tab includes the following:
- Reference
- Specify the reference port used for skew calculation. Typically,
this is the clock port of a source-synchronous output interface.
The equivalent Tcl option is:
-group - Ports
- Add additional ports to include in the same group.
- Click the + (plus) button to create a new group with its own reference port
- Click the – (minus) button to remove an existing group of ports
- Reference
- Specifies the reference port for skew calculation. In most cases, this is a
clock port of a source synchronous output interface.
The equivalent Tcl option is:
-group - Ports
- Defines additional ports to report. Notice the + and -
(plus and minus) buttons to the right of the Ports field.
- The + button specifies multiple groups, each with its own reference clock port. You can define a new group of ports, including a new reference port.
- The - button removes additional groups of ports as needed.