Abstract: Structures and methods for controlling operation of a programmable impedance element are disclosed herein. In one embodiment, a method of controlling a programmable impedance element can include: (i) receiving a program or erase command to be executed on the programmable impedance element; (ii) selecting an operation algorithm for executing the command, where the operation algorithm is selected from among a plurality of operation algorithms by decoding at least two bits stored in a register; (iii) determining, using the register, a plurality of option variables for the selected operation algorithm, where the option variables are used to set conditions for one or more of a plurality of program and erase operations of the selected operation algorithm; and (iv) executing the command on the programmable impedance element by performing the one or more of the plurality of program and erase operations of the selected operation algorithm.