W78C51D

Preliminary W78C51D 8-BIT MICROCONTROLLER GENERAL DESCRIPTION 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. FEATURES Fully static design Supply voltage of 4.5V to 5.5V DC-40 MHz operation 128 bytes of on-chip scratchpad RAM 4K bytes of on-chip mask ROM 64K bytes program memory address space 64K bytes data memory address space Four 8-bit bidirectional ports Two 16-bit timer/counters One full duplex serial port Seven-source, two-level interrupt capability One extra 4-bit bit-addressable I/O port Two additional external inter...