Equivalent Driver Merging - 2021.2 English

Vivado Design Suite User Guide: Implementation (UG904)

Document ID
UG904
Release Date
2021-11-24
Version
2021.2 English

Reduces the drivers of all logically-equivalent signals to single drivers. This is similar to control set merging but is applied to all signals, not only control signals.

You can limit the scope of equivalent driver and control set merging by using the EQUIVALENT_DRIVER_OPT cell property. Setting the EQUIVALENT_DRIVER_OPT property to MERGE on the original driver and its replicas triggers the merge equivalent driver phase during opt_design and merges the drivers with that property. Setting the EQUIVALENT_DRIVER_OPT property to KEEP on the original driver and its replicas prevents the merging of the drivers with that property during the equivalent driver merging and the control set merging phase.

Note: Some interfaces require a one to one mapping from FF driver to interface pin and merging these logically-equivalent signals to a single driver can result in unroutable nets. In that case set a DONT_TOUCH property to TRUE or set the EQUIVALENT_DRIVER_OPT property to KEEP on those registers.