US Patent 9640244 Pre-calibration for multiple performance states

A method and apparatus for pre-calibration of various system performance states is disclosed. In one embodiment, a method includes, for each of a number of different performance states (or operating points), performing initial calibrations of various parameters associated with transfers of data between a memory and a memory controller. After completing the initial calibrations, the calibrated values are stored. Thereafter, during normal operation and following a change to a new performance state, the values of the various parameters are set to the values to which they were calibrated during the initial calibration for that state.