General Description

The Enhanced I/O MCUs are a series of 8-bit high performance, RISC architecture microcontrollers specifically designed for a wide range of applications. The usual Holtek microcontroller features of low power consumption, I/O flexibility, timer functions, oscillator options, power down and wake-up functions, watchdog timer and low voltage reset, combine to provide devices with a huge range of functional options while still maintaining a high level of cost effectiveness. The fully integrated system oscillator HIRC, which requires no external components and which has three frequency selections, opens up a huge range of new application possibilities for these devices, some of which may include industrial control, consumer products, household appliances subsystem controllers, etc.

Features

CPU Features

• Operating voltage:

fSYS = 4MHz: 2.2V~5.5V

fSYS = 8MHz: 3.3V~5.5V

fSYS = 12MHz: 4.5V~5.5V

• Up to 0.33μs instruction cycle with 12MHz system clock at VDD= 5V

• Oscillator types:

External high freuency Crystal -- HXT

External RC -- ERC

Internal RC -- HIRC

External low frequency crystal -- LXT

• Three operational modes: Normal, Slow, Sleep

• Fully integrated internal 4MHz, 8MHz and 12MHz oscillator requires no external components

• Watchdog Timer function

• LIRC oscillator function for watchdog timer

• All instructions executed in one or two instruction cycles

• Table read instructions

• 63 powerful instructions

• Up to 6-level subroutine nesting

• Bit manipulation instruction

• Low voltage reset function

• Wide range of available package types

Peripheral Features

• Up to 26 bidirectional I/O lines

• Software controlled 4-SCOM lines LCD driver with 1/2 bias

• External interrupt input shared with an I/O line

• Up to three 8-bit programmable Timer/Event Counter with overflow interrupt and prescaler

• Time-Base function

• Programmable Frequency Divider -- PFD