a controller is described that includes wiring to transport notification that a fifo that holds data to be used to display content on a display has reached a threshold . the controller also includes first control circuitry to turn on a phase locked loop circuit to cause logic circuitry within the controller downstream from the pll to begin to receive a first clock in response to the notification . the logic circuitry is to transport data read from a memory toward the fifo . the controller also includes second control circuitry to cause the memory to use a second clock provided by the controller in response to the notification .