Patent ID: 8867595

Claim:
A method for calibrating a reference voltage generated at a first node in a receiver of a single-ended signaling system, wherein the reference voltage is compared against a signal received at a second node in the receiver from a transmitter of the single-ended signaling system, wherein the first node and the second node are the inputs to a differential amplifier, and wherein the outputs of the differential amplifier are the inputs to a sampler which samples the difference between a value at the first node and a value at the second node, the method comprising: receiving a signal at the second node in the receiver, wherein the signal includes a calibration pattern which comprises substantially equally balanced 1's and 0's; adjusting a voltage value at the first node monotonically in a first mode while monitoring outputs of the sampler; recording a first voltage value at the first node when a second logic value is detected among the outputs of the sampler; adjusting the voltage value at the first node monotonically in a second mode while monitoring the outputs of the sampler; recording a second voltage value at the first node when a first logic value is detected among the outputs of the sampler; and determining a value for the reference voltage based on the first voltage value and the second voltage value.