The AD5231 provides nonvolatile memory digitally controlled potentiometers2 with 1024-position resolution. These devices perform the same electronic adjustment function as a mechanical potentiometer. The AD5231's versatile programming via a standard 3-wire serial interface allows 16 modes of operation and adjustment, including scratch pad programming, memory storing and retrieving, increment/decrement, log taper adjustment, wiper setting read back, and extra user-defined EEMEM. In the scratch pad programming mode, a specific setting can be programmed directly to the RDAC2 register, which sets the resistance at terminals W-A and W-B. The RDAC register can also be loaded with a value previously stored in the EEMEM1 register. The value in the EEMEM can be changed or protected. When changes are made to the RDAC register, the value of the new setting can be saved into the EEMEM. Thereafter, such value will be transferred automatically to the RDAC register during system power ON. It is enabled by the internal preset strobe. EEMEM can also be retrieved through direct programming and external preset pin control.