The µPD178004A, 178006A, 178016A, and 178018A are 8-bit single-chip CMOS microcontrollers that incorporate hardware for digital tuning systems. The CPU uses the 78K/0 architecture, which makes it easy to implement high-speed access to internal memory and control of peripheral hardware. The instructions used are the high-speed 78K/0 instructions, suitable for system control. The rich assortment of peripheral hardware includes an input/output port, 8-bit timer, A/D converter, serial interface, power-ON clear circuits, as well as a pre-scaler for digital tuning, a PLL frequency synthesizer, and a frequency counter. The µPD178P018A, one-time PROM or EPROM versions which can be operated in the same supply voltage range as for the mask ROM versions, and various development tools, are also available.