1. A memory device, comprising: a controller configured to operate in a voltage mode and a current mode to transition a memory cell between high and low resistance states, the controller comprising: a selector configured to select operation of the controller in the voltage mode or the current mode; a voltage ramp node configured to produce a decreasing voltage programming signal for application to the memory cell in the voltage mode; and a current ramp node configured to produce a decreasing current programming signal for application to the memory cell in the current mode, wherein the controller is configured to apply the decreasing voltage programming signal or the decreasing current programming signal to the memory cell after the memory cell enters the melting phase to transition the memory cell between the high and low resistance states.