A system and method is disclosed that efficiently provides standard termination blocks in an approved cell library that are flexible and customizable. A serial communications system includes a transmitter for sending a serial data signal at an output of the transmitter; a transmitter terminator, coupled to the output and responsive to a first configuration signal, to variably terminate a first selected property of the output; a receiver for processing the serial data signal at an input of the receiver, the input of the receiver coupled to the output of the transmitter; and a receiver terminator, coupled to the input of the receiver and responsive to a second configuration signal to variably terminate a second selected properly of the input. The method for operating a serial communications system includes the steps of: (a) providing a plurality of unidirectional serial links, each of the links between a transmitter and a receiver, an output of each transmitter coupled to an input of a corresponding receiver by a medium type with each output having a transmitter terminator and each input having a receiver terminator; (b) terminating variably a selected property of the output of each transmitter to match the medium type coupling the output to the input of the corresponding receiver by use of a transmitter termination configuration signal asserted to the transmitter; and (c) terminating variably a selected property of the input of each receiver to match the medium type coupling the input to the output of the corresponding transmitter by use of a receiver termination configuration signal asserted to the receiver.