Data processing having multiple low power modes and method therefor

摘要

A method is provided for operating a data processing system having a memory. The memory is coupled between a first power supply voltage terminal for receiving a first variable potential and a second power supply voltage terminal for receiving a second variable potential. An initial difference between the first variable potential and the second variable potential is not less than a first voltage. The method comprises: receiving a command to transition the data processing system from a first power supply voltage to a second power supply voltage; changing the second variable potential so that a difference between the second variable potential and the first variable potential is greater than the first voltage; and after changing the second variable potential, changing the first variable potential, wherein a difference between the first variable potential and the second variable potential is not less than the first voltage.