General Description
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.

FEATUREs
■ Built-in 6502 8-bit CPU
■ 2 MHz CPU operation frequency
■ 4K bytes of ROM
■ 128 bytes of SRAM
■ One 8-bit programmable base timer with 1 - 256 msec interval
■ 29 programmable bi-directional I/O pins
■ 3 LED direct sink pins with internal serial resistors
■ Mask optional for built-in RC oscillator with an external resistor or external ceramic resonator applied
■ Watch-dog timer
■ Built-in power-on reset
■ Built-in low voltage reset
■ CMOS technology for low power consumption
■ Available in 40 pin DIP package and 40 pad CHIP FORM