Rainbow Electronics W78C51D - Manual

Preliminary W78C51D
8-BIT MICROCONTROLLER
Publication Release Date: January 1999
- 1 - Revision A1
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 interrupts INT2 / INT3
• Watchdog timer
• EMI reduction mode
•
Built-in power management
• Code protection
• Packages:
− DIP 40: W78C51D-24/40
− PLCC 44: W78C51DP-24/40
− QFP 44: W78C51DF-24/40