The LC723700 Series are large-capacity ETR microcontrollers that achieve an instruction execution time of 1.33 s and provide up to 64 KB of ROM and up to 2 KB of RAM. They include an on-chip high-performance PLL circuit that features an added high-speed lock circuit and can control the C/N characteristics of a local oscillator. They also provide a rich set of on-chip interface circuits, including a 3-channel serial I/O port, and an 8input 8-bit A/D converter.