Overview
The LC66354B, LC66356B and LC66358B are 42-pin package four-bit CMOS microcontrollers that integrate on a single chip all functions required in a control microcontroller, including ROM, RAM, I/O ports, serial interfaces, comparator inputs, three-value inputs, timers and an interrupt system. These products differ from the earlier LC66358A series in their power supply voltage range and operating speed specifications.

FEATUREs and Functions
• ROM (with 4 K-, 6 K- and 8 K-byte capacities) and RAM (512 4-bit digits) on chip
• LC66000 series compatible instruction set (128 instructions)
• A total of 36 I/O port pins
• Two eight-bit serial interfaces that can be connected in cascade to form a 16-bit interface
• Instruction cycle time: 0.92 to 10 µs (3 to 5.5 V)
    The earlier LC66358A series had instruction cycle times of from 1.96 to 10 µs (at 3 to 5.5 V) and from 3.92 to 10 µs (at 2.2 to 5.5 V).
• Powerful timer and prescaler functions
    Time limit timer, event counter, pulse width measurement and square wave output using a 12-bit timer.
    Time limit timer, event counter, PWM output and square wave output using an 8-bit timer.
    Time base function using a 12-bit prescaler.
• Powerful interrupt system with eight interrupts and eight vector locations
    External interrupts: three interrupts and three vector locations
    Internal interrupts: five interrupts and five vector locations
• Flexible I/O functions
    Comparator inputs, three-value inputs, 20 mA drive outputs, 15 V withstand voltage, pull-up or open-drain option switching
• Runaway detection function (watchdog timer) option
• Eight-bit I/O function
• Power reduction functions using halt and hold modes
• Packages: DIP42S, QIP48E (QFP48E)
• Evaluation LSI: used together
    — LC66599 (evaluation chip) + EVA850/800-TB6630X
    — LC66E308 (on-chip EPROM microcontroller)