The Xicor X9C303 is a digitally controlled potentiometer (XDCP). The device consists of a resistor array, wiper switches, a control section, and nonvolatile memory. The wiper position is controlled by a threewire interface. The resistor array is composed of 99 resistive elements. Between each element and at either end are tap points accessible to the wiper terminal. The position of the wiper element is controlled by the CS, U/D, and INC inputs. The position of the wiper can be stored in nonvolatile memory and then be recalled upon a subsequent power-up operation. The device can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications ranging from control, to signal processing, to parameter adjustment. Digitallycontrolled potentiometers provide three powerful application advantages; (1) the variability and reliability of a solid-state potentiometer, (2) the flexibility of computer-based digital controls, and (3) the use of nonvolatile memory for potentiometer settings retention.