The X9C102/103/104/503 is a resistor array composed of 99 resistive elements. Between each element and at either end are tap points accessible to the wiper element. 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 resolution of the X9C102/103/104/503 is equal to the maximum resistance value divided by 99. As an example, for the X9C503 (50K) each tap point represents 505. All Xicor nonvolatile memories are designed and tested for applications requiring extended endurance and data retention.