General Description
HT1670 is a peripheral device specially designed for I/O type MCU used to expand the display capability. The max. display segment of the device are 4096 patterns (128 segments and 32 commons). It also supports four data bits interface, buzzer sound, Watchdog Timer or time base timer functions. The HT1670 is a memory mapping and multi-function LCD controller.

Features
• Operating voltage: 2.7V~5.2V
• Built-in 32kHz RC oscillator
• External 32.768kHz crystal oscillator or 32kHz frequency source input
• Standby current: <1μA at 3V, <2μA at 5V
• Internal resistor type: 1/6 bias or 1/5 bias, 1/32 duty, and 1/16 duty
• Three selectable LCD frame frequencies: 64Hz, 89Hz or 170Hz
• Max. 128x32 patterns, 128 segments and 32 commons
• 144 segments and 16 commons selectable by command method
• Built-in bit-map display RAM: 4096 bits (=128x32 bits)
• Built-in internal resistor type bias generator
• Six-wire interface (four data wires)
• Eight kinds of time base/WDT selection
• Time base or WDT overflow output
• R/W address auto increment
• Built-in buzzer driver (2kHz/4kHz)
• Power down command reduces power consumption
• Software configuration feature
• Data mode and Command mode instructions
• Three data accessing modes
• Provides VLCD pin to adjust LCD operating voltage and max. VLCD voltage up to 7V
• Provides three kinds of bias current programming
• Control of TN-type and STN-type LCDs
• 208-pin QFP package

Applications
• Leisure products
• Games
• Personal digital assistant
• Cellular phone
• Global positioning system
• Consumer electronics