Techniques are provided for individually adjusting the on-chip termination impedance that is generated by input and output (IO) buffers in an input/output (IO) bank on an integrated circuit. The IO buffers in an IO bank can generate different on-chip termination impedances. And as a result, an IO bank can support more than one class of memory interfaces. An OCT calibration block generates a digital on-chip termination (OCT) calibration code. In some embodiments, circuitry in the IO banks can be configured to shift the OCT calibration code by one or more bits to adjust the series and/or parallel on-chip termination impedance in one or more IO buffers.