SH68689

SH68689 Keyboard Controller Features „ Built-in 6502 8-bit CPU „ 2MHz CPU operation frequency „ 8K bytes of ROM „ 160 bytes of SRAM „ One 8-bit programmable base timer with 1 - 256 µsec interval „ 29 programmable bi-directional I/O pins „ 3 LED direct sink pins with internal serial resistors „ Built-in RC oscillator with an external resistor „ Mask option for DATA/CLK and I/O Port driving capability „ Watch-dog timer „ Built-in power-on reset „ Built-in low voltage reset „ CMOS technology for low power consumption „ Available in CHIP FORM General Description SH68689 is a single chip micro-controller for keyboard applications. It incorporates a 6502 8-bit CPU core, 8K bytes of ROM and 160 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 only requires an externally applied resistor, and a watch-dog timer preventing system standstill. 1 V2.0 Block Diagram SH68689 TIMING GENERATOR (RC OSC 4MHz) 8K BYTES ROM 6502 CPU 160 BYTES SRAM+STACK RESET VDD GND INT. CONTROLLER POWER-ON RESET/ LOW VOLTAGE RESET WATCH DOG TIMER BASE TIMER I/O PORTS CLK DATA LED 0 LED 1 LED 2 P00-P07 P10-P17 P20-P27 P30-P37 2 SH68689 Electrical Characteristics Absolute Maximum Ratings* DC Supply Voltage . . . . . . . . . . . . . . . . . . . . .-0.3V to +7.0V Input/Output Voltage . . . . . . . . . . GND - 0.3V to VDD ...