Timing - Types of Relative Propagation Delay

Relative Propagation Delay describes the timing relationship between PinPairs.

 

There's three types of RelProp Timing in Constraint Manager.

CCS organizes RelProp Timing relationships into these three types of timing for you - Simple Match, Match with Target and Relative Timing.

Simple Match

Simple Match matches all the Pin Pairs in a Match Group to each other.

There's no Target and Delta is blank.

Simple Match constrains to meet the Design Intent:

Match all Pin Pairs within 100 mils.

Match with Target

Match with Target matches all Pin Pairs within the Match Group +/- to the Target.

The Target is centered in the Match Group and the Delta is 0.

Simple with Target constrains to meet the Design Intent:

Match all Pin Pairs +/- 100 mils to the Clock.

Match Range vs Tolerance

Tolerance is the Match Group constraint that defines the timing relationships.

Tolerance has different meanings depending on the type of timing and the value of Delta.

CCS helps make this clear by defining by showing the Match Range and Tolerance for each type of timing.

This is shown in the constraint grid and visually in the VISUEYES Match Group Timing display.

Relative Timing

Relative Timing is for complex timing within the Match Group.

There is a Target and multiple relationships to the Target, with multiple Deltas.

Relative Timing can meet cpmplex timing Design Intent:

Delta - Locate Range to Target

Delta locates the centerline of match ranges to the Target.

This becomes more visible in the VISUEYES Display.

A positive Delta places the centerline to the right of the Target.

Anegative Delta places the centerline to the left of the Target.