GENERAL DESCRIPTION
The W78E58 is an 8-bit microcontroller that is functionally compatible with the W78C58, except that the mask ROM is replaced by a flash EEPROM with a size of 32 KB. To facilitate programming and verification, the flash EEPROM inside the W78E58 allows the program memory to be programmed and read electronically. Once the code is confirmed, the user can protect the code for security. The W78E58 microcontroller supplies a wider frequency range than most 8-bit microcontrollers on the market. It is functionally compatible with the industry-standard 80C52 microcontroller series, except that one extra 4-bit bit-addressable I/O port(Port 4) and two additional external interrupts (INT2 , INT3 ).
The W78E58 contains four 8-bit bi-directional and bit-addressable I/O ports, three 16-bit timer/counters, and a serial port. These peripherals are supported by a eight-source, two-level interrupt capability. There are 256 bytes of RAM and an 32 KB flash EEPROM for application programs.
The W78E58 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
● 8-bit CMOS microcontroller
● Fully static design
● Low standby current at full supply voltage
● DC-40 MHz operation
● 256 bytes of on-chip scratchpad RAM
● 32 KB electrically erasable/programmable EPROM
● 64 KB program memory address space
● 64 KB data memory address space
● Four 8-bit bidirectional ports
● One extra 4-bit bit-addressable I/O port, additional INT2 / INT3 (available on 44-pin PLCC/QFP package)
● Three 16-bit timer/counters
● One full duplex serial port
● Boolean processor
● Eight-source, two-level interrupt capability
● Built-in power management
● Code protection mechanism
● Packages:
   - DIP 40: W78E58-16/24/40
   - PLCC 44: W78E58P-16/24/40
   - QFP 44: W78E58F-16/24/40
   - TQFP 44: W78E58M-16/24/40