Power control of a memory device through a sideband channel of a memory bus

Abstract

A method is described that includes choosing between one of two different ways to cause a memory device to enter a specific one of multiple lower power states that each comprise lower power consumption than a highest low power state. The method also includes asserting a first signal on a first signal line that is coupled to a power management controller of the memory device to indicate to the power management controller that a sideband channel of a memory bus that is coupled to the memory device is activated. The method also includes causing the memory device to enter the specific one of the multiple lower power states by also performing the chosen one of a) sending an in-band signal on said memory bus coupled with said asserting of said first signal, said in-band signal specifying the specific one of the multiple lower power states; or, b) sending a second signal on a second signal line that identifies the specific one of the multiple lower power states.