W78C51D

The W78C51D microcontroller supplies a wider frequency and supply voltage range than most 8-bit microcontrollers on the market. It is compatible with the industry standard 80C51 microcontroller series.

The W78C51D contains four 8-bit bidirectional parallel ports, one extra 4-bit bit-addressable I/O port (Port 4) and two additional external interrupts (INT2 , INT3 ), two 16-bit timer/counters, one watchdog timer and a serial port. These peripherals are supported by a seven-source, two-level interrupt capability. There are 128 bytes of RAM and an 4K byte mask ROM for application programs.

The W78C51D microcontroller has two power reduction modes, idle mode and power-down mode, both of which are software selectable. The idle mode turns off the processor clock but allows for continued peripheral operation. The power-down mode stops the crystal oscillator for minimum power consumption. The external clock can be stopped at any time and in any state without affecting the processor.