A method and apparatus for automated calibration of I/O over a multi-variable eye window is provided. A transmitter may conduct data transmissions to a receiver of an integrated circuit (IC) over a plurality of signal lines. The data transmissions may be conducted according to a certain parameters or sets of parameters. Parameters may include voltage levels at which signals are transmitted or timing delays. The receiver may determine whether the correct data value was received over each signal line. The results may be recorded in a storage mechanism in the same IC as the receiver. The storage mechanism may, for each signal line, store a pass/fail result corresponding to the particular parameters for the data transmission. The system may select the parameters which subsequent transmissions are to be conducted over each of the plurality of signal lines from the storage mechanism.