W78E51B_05 Datasheet, PDF (3/25 Pages) Winbond – 8-BIT MICROCONTROLLER

W78E51B
1. GENERAL DESCRIPTION
The W78E51B is an 8-bit microcontroller which can accommodate a wider frequency range with low
power consumption. The instruction set for the W78E51B is fully compatible with the standard 8051.
The W78E51B contains an 4K bytes Flash EPROM; a 128 bytes RAM; four 8-bit bi-directional and bit-
addressable I/O ports; an additional 4-bit I/O port P4; two 16-bit timer/counters; a hardware watchdog
timer and a serial port. These peripherals are supported by seven sources two-level interrupt
capability. To facilitate programming and verification, the Flash EPROM inside the W78E51B allows
the program memory to be programmed and read electronically. Once the code is confirmed, the user
can protect the code for security.
The W78E51B 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.
2. FEATURES
y Fully static design 8-bit CMOS microcontroller
y Wide supply voltage of 4.5V to 5.5V
y 128 bytes of on-chip scratchpad RAM
y 4 KB On-chip Flash EPROM
y 64 KB program memory address space
y 64 KB data memory address space
y Four 8-bit bi-directional ports
y One extra 4-bit bit-addressable I/O port, additional ^INT2 / ^INT3
(available on 44-pin PLCC/QFP package)
y Two 16-bit timer/counters
y One full duplex serial port(UART)
y Watchdog Timer
y Seven sources, two-level interrupt capability
y EMI reduction mode
y Built-in power management
y Code protection mechanism
y Packages:
− DIP 40: W78E51B-40
− PLCC 44: W78E51BP-40
− PQFP 44: W78E51BF-40
− Lead Free (RoHS) DIP 40: W78E051B40DL
− Lead Free (RoHS) PLCC 44: W78E051B40PL
− Lead Free (RoHS) PQFP 44: W78E051B40FL
Publication Release Date: Sep. 6, 2005
-3-
Revision A7