@User How are liberty files used with IO cells?

I know that openlane requires liberty files for the I/O because for top-level routing they are treated like any other hard macro in the synthesis flow.

@Tim 'mithro' Ansell @Tim Edwards Liberty files for IO cells (can) also contain timing data and timing constraints can also be put on IO signals so STA can check whole path from signal going into chip and the output coming out of the chip. For example output signal available within a certain after the clock edge.