Patent ID: 8065570

Claim:
An integrated circuit (IC), comprising: a plurality of output circuits including terminations having configurable termination impedance, wherein the output circuits are configurable to implement one of a plurality of different termination impedances when active; a plurality of digitally controlled impedance (DCI) modules coupled to the configurable terminations of the plurality of output circuits; a plurality of select circuits having outputs coupled to enable terminals of the plurality of DCI modules, wherein when operating the IC in a test mode, the plurality of select circuits is configured to selectively couple first control signals to the enable terminals of the plurality of DCI modules, wherein the first control signals enable only one DCI module of the plurality of DCI modules at a time, and wherein when operating the IC in the test mode, a reference source external to the IC is coupled to the plurality of DCI modules, wherein the reference source provides second control signals to each of the plurality of DCI modules, and wherein each DCI module selects a same termination impedance for each of the terminations responsive to the second control signals.