Controllers, interfaces, memory devices, methods and systems are disclosed, including a controller configured to interface with a separate memory device and perform an iterative write operation to program a selected memory cell of the memory device to a target state, wherein each iteration of the write operation is configured to successively change a physical state of the selected memory cell. Other controllers, interfaces, memory device, methods and systems are also described, such as those where either a controller or a memory device can throttle a data communication operation, and/or those that utilize customized programming pulses.