
Preliminary W77IE58
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GENERAL DESCRIPTION
The W77IE58 is a fast 8051 compatible microcontroller with a redesigned processor core without wasted
clock and memory cycles. As a result, it executes every 8051 instruction faster than the original 8051 for
the same crystal speed. Typically, the instruction executing time of W77IE58 is 1.5 to 3 times faster
then that of traditional 8051, depending on the type of instruction. In general, the overall performance is
about 2.5 times better than the original for the same crystal speed. Giving the same throughput with
lower clock speed, power consumption has been improved. Consequently, the W77IE58 is a fully static
CMOS design; it can also be operated at a lower crystal clock. The W77IE58 contains 32 KB flash
Multiple-Time Programmable Flash ROM, and provides operating voltage from 2.7V to 5.5V. All W77IE58
types also support on-chip 1 KB SRAM without external memory component and glue logic, saving more
I/O pins for users’ application usage if they use on-chip SRAM instead of external SRAM.
FEATURES
8-bit CMOS microcontroller
High speed architecture of 4 clocks/machine cycle runs up to 25 MHz
Pin compatible with standard 80C52
Instruction-set compatible with MCS-51
Four 8-bit I/O Ports
One extra 4-bit I/O port and Wait State control signal (available on 44-pin PLCC/QFP package)
Three 16-bit Timers
12 interrupt sources with two levels of priority
On-chip oscillator and clock circuitry
Two enhanced full duplex serial ports
32 KB flash Multiple-Time Programmable( FLASH) ROM
256 bytes scratch-pad RAM
1 KB on-chip SRAM for MOVX instruction
Programmable Watchdog Timer
Dual 16-bit Data Pointers
Software programmable access cycle to external RAM/peripherals
Packages:
DIP 40: W77IE58-25
PLCC 44: W77IE58P-25