CPU Features

Operating Voltage
fSYS= 8MHz: 2.2V~5.5V
fSYS= 10MHz: 2.7V~5.5V
fSYS= 12MHz: 3.3V~5.5V
fSYS= 16MHz: 4.5V~5.5V
Up to 0.25μs instruction cycle with 16MHz system clock at VDD=5V
Power down and wake-up functions to reduce power consumption
Four Oscillators:
– External High Frequency Crystal — HXT
– External 32.768kHz Crystal– LXT
– Internal High Frequency RC — HIRC
– Internal 32kHz — LIRC
Fully intergrated internal 8MHz oscillator requires no external components
Multi-mode operation: NORMAL, SLOW, IDLE and SLEEP
All instructions executed in one to three instruction cycles
Table read instructions
115 powerful instructions
8-level subroutine nesting
Bit manipulation instruction

Peripheral Features

Flash Program Memory: 8Kx16 (HT66F489)/4Kx16 (HT66F488)
RAM Data Memory: 384×8
True EEPROM Memory: 64×8
Watchdog Timer function
30 bidirectional I/O lines
LED driver
1/3 Bias Software LCD
Serial Interface Module — SIM for SPI or I2C
UART Function
Six pin-shared external interrupts
Multiple Timer Module for time measure, input capture, compare match output, PWM output function or single pulse output function
Dual Time-Base functions for generation of fixed time interrupt signals
8-channel 12-bit resolution A/D converter
Low voltage reset function
Low voltage detector function
Package: 28-pin SOP/SSOP