General Description
The APU4003T is an EEPROM-equipped high- performance 4-bit microcomputer. It contains not only all functions compatible with APU4003T, but also an EEPROM, providing customers such conveniences as on-board verification, customized code, small quantity sample production, etc.
This chip especially provides a security bit to protect the customer’s code.

Features
• Very low current dissipation.
• Wide operating voltage range.
• Supports both Ag and Li batteries.
• Powerful instruction set.
• 4-level subroutine nesting (including interrupt).
• 4 event-driven interrupts, 2 external and 2 internal.
• ROM size: 1024x15 bits.
• RAM size: 64x4 bits.
• Input ports: 2 ports/ 8 pins (S and M).
• Output port: 1 port/ 4 pins (P).
• Pseudo serial output port (P).
• Input/Output ports: 2 ports/ 8 pins (I/OA and I/OB).
• Control outputs: ALARM, LIGHT.
• LCD driver outputs (can drive up to 75 LCD segments).
• PROM option to select 4 LCD drive modes: static, duplex (1/2 duty 1/2 bias, 1/3 duty 1/2 bias or 1/3 duty 1/3 bias).
• PROM option permits LCD driver output pins to be used for DC output ports; up to 25 pins are available.
• Segment PLA circuit permits any layout on LCD panel.
• Built-in clock generator (crystal or RC).
• Built-in voltage doubler, halver, tripler.
• Endurance: More then 100 write cycles/word.
• Security bit for read/write protection.