The µPD17145(A1), 17147(A1), and 17149(A1) are 4-bit single-chip microcontrollers integrating an 8-bit A/D converter (4 channels), a timer function (3 channels), and a serial interface. These microcontrollers employ a CPU of the general-purpose register type that can execute direct memory operations and direct memory-to-memory data transfer for efficient programming. All the instructions consist of 16 bits per word. In addition, a one-time PROM version, the µPD17P149, is also available for program evaluation.