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Using TPTHRU or TPSYNC in a FROM-TO Constraint

It is sometimes convenient to define intermediate points on a path to which a specification applies. This defines the maximum allowable delay and has the following syntax.

Schematic syntax in TIMESPEC primitive

TSidentifier=FROM source_group THRU thru_point [THRU thru_point] TO dest_group allowable_delay [units]

TSidentifier=FROM source_group THRU thru_point [THRU thru_point] allowable_delay [units]

TSidentifier=THRU thru_point [THRU thru_point] TO dest_group allowable_delay [units]

UCF syntax

TIMESPEC TSidentifier=FROM source_group THRU thru_point [THRU thru_point] TO dest_group allowable_delay [units];

TIMESPEC TSidentifier=FROM source_group THRU thru_point [THRU thru_point] allowable_delay [units];

TIMESPEC TSidentifier=THRU thru_point [THRU thru_point] allowable_delay [units];

Unspecified FROM or TO, as in the second and third syntax statements, implies all points.

The example shows how to use the TPTHRU attribute with the THRU attribute on a schematic. The UCF syntax is as follows.

INST FLOPA TNM=A;
INST FLOPB TNM=B;
NET MYNET TPTHRU=ABC
TIMESPEC TSpath1=FROM A THRU ABC TO B 30;

The following schematic shows the placement of the TPTHRU attribute and the resultant path that is defined.

Figure 4.18 TPTHRU Example

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