User guide

xi
Disabling CELLTYPE Checking in SDF Files . . . . . . . . . . . . 13-15
The SDF Configuration File . . . . . . . . . . . . . . . . . . . . . . . . . . 13-16
Delay Objects and Constructs . . . . . . . . . . . . . . . . . . . . . 13-17
SDF Configuration File Commands . . . . . . . . . . . . . . . . . 13-18
SDF Example with Configuration File. . . . . . . . . . . . . . . . 13-25
Understanding the DEVICE Construct . . . . . . . . . . . . . . . . . . . . 13-28
Handling Backannotation to I/O Ports . . . . . . . . . . . . . . . . . . . . . 13-30
Using the INTERCONNECT Construct . . . . . . . . . . . . . . . . . . . . 13-31
Multiple Backannotations to Same Delay Site. . . . . . . . . . . . . . . 13-31
INTERCONNECT Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-32
Multisource INTERCONNECT Delays. . . . . . . . . . . . . . . . . . 13-32
Omitting the +multisource_int_delays Option. . . . . . . . . . 13-34
Simultaneous Multiple Source Transitions . . . . . . . . . . . . 13-35
Single Source INTERCONNECT Delays . . . . . . . . . . . . . . . . 13-36
Min:Typ:Max Delays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-37
Specifying Min:Typ:Max Delays at Runtime. . . . . . . . . . . . . . 13-38
Using the Configuration File to Disable Timing . . . . . . . . . . . . . . 13-39
Using the timopt Timing Optimizer . . . . . . . . . . . . . . . . . . . . . . . 13-40
Editing the timopt.cfg File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-43
Editing Potential Sequential Device Entries. . . . . . . . . . . . . . 13-43
Editing Clock Signal Entries. . . . . . . . . . . . . . . . . . . . . . . . . . 13-44
14. Negative Timing Checks
The Need for Negative Value Timing Checks . . . . . . . . . . . . . . . 14-2