A physical memory interface (Phy) and method of operating is disclosed. The Phy interface includes command and status registers (CSRs) configured to receive a first power context and second power context. Selection circuitry is configured to switch between the first and second power contexts. A plurality of adjustable delay elements are provided, each having a delay time responsive to the selected power context. A first set of CSRs configured may store the first power context and a second set of CSRs configured may store the second power context. The Phy interface may also include a plurality of drivers each having a selectable drive strength responsive to the selected power context. The Phy interface may also include a plurality of receivers each having a selectable termination impedance responsive to the selected power context. Switching between power contexts may result in adjusting of the delay elements, drive strength and/or termination impedance of one or more drivers/receivers.