GENERAL DESCRIPTION
MTU8B5X series is an EPROM based 8-bit microcontroller which employs a full CMOS technology
enhanced with low-cost, high speed and high noise immunity. Watchdog Timer, RAM, EPROM, tri-state I/O port, power down mode, and real time program mable clock/counter are integrated into this chip. MTU8B5X contains 33 instructions, all are single cycle except for program branches which take two cycles.
On chip memory is available with 512x14 bits of EPROM for MTU8B54E/55E, 1Kx14 bits of EPROM
for MTU8B56E, 2Kx14 bits of EPROM for MTU8B57E and 24 to 72 bytes of static RAM. 

FEATURES
• Total of 33 single word instructions .
• The fast execution time may be 200ns for all single
cycle instructions under 20MHz operating.
• Operating voltage range: 2.3V ~ 6.5V
• 8-bit data bus.
• 14-bit instruction word.
• Four-level stacks.
• On chip EPROM size : 512x14 bits for MTU8B54E/55E,  1Kx14 bits for MTU8B56E, 2Kx14 bits forMTU8B57E.
• Internal RAM size : 25 bytes for MTU8B54E/56E, 24 bytes for MTU8B55E, 72 bytes for MTU8B57E.
• Direct and indirect addressing modes for data accessing
• 8-bit real time clock/counter with 8-bit programmable prescaler.
• Internal power-on Reset.
• Device Reset Timer.
• Code protection.
• Sleep mode for power saving.
• On chip Watchdog Timer(WDT) based on internal RC oscillator.
• Three I/O ports PA, PB nad PC with independent direction control.
•   4 types of oscillator can be selected by code options:
- RC : Low-cost RC oscillator
- XTAL : Standard crystal oscillator
- HFXTAL : High frequency crystal oscillator
- LFXTAL : Low frequency crystal oscillator