The PD178004A, 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. Also, the instructions used are the high-speed 78K/0 instructions, suitable for system control.