The GPIO IP allows you to pack registers into the periphery to save area and resource utilization.
You can configure the full-rate DDIO on the input and output path as a flip flop by adding .qsf assignments.
| Path | .qsf Assignment |
|---|---|
| Input register packing | set_instance_assignment -name FAST_INPUT_REGISTER ON -to <path to register> |
| Output register packing | set_instance_assignment -name FAST_OUTPUT_REGISTER ON -to <path to register> |
| Output enable register packing | set_instance_assignment -name FAST_OUTPUT_ENABLE_REGISTER ON -to <path to register> |
Note: The .qsf
assignments do not guarantee register packing. However, these assignments enable the
Fitter to find a legal placement. Otherwise, the Fitter keeps the flip flop in the core.
When you set the Output Enable Register Packing to ON, you
must set the Output Register Packing to ON.