NT6868A is a single chip micro-controller for keyboard applications. It incorporates a 6502 8-bit CPU core, 4K bytes of ROM, and 128 bytes of RAM used as working RAM and stack area. It also includes 29 programmable bi-directional I/O pins and one 8-bit pre-loadable base timer. Additionally, it includes a built-in low voltage reset, a 4MHz RC oscillator that requires only a resistor externally applied or a 4MHz ceramic resonator, and a watch-dog timer that prevents system standstill.
