The PD17068 is a 4-bit single-chip microcontroller for digital tuning systems. It contains an image display controller (IDC) that supports many types of display, and a PLL synthesizer. The CPU of the PD17068 is capable of 4-bit parallel addition, logical operations, bit tests, setting/resetting of a carry flag, and supports a powerful interrupt function and timer function. The image display controller for on-screen display is user-programmable, allowing a range of displays to be programmed.