General Description
HT1650 is a peripheral device specially designed for I/O type MCUs which are used to expand the display capability. The max. display segment of the device are 2048 patterns (64 segments and 32 commons). It also supports four data bits interface, buzzer sound, Watchdog Timer or time base timer functions. The HT1650 is a memory mapping and multi-function LCD controller. It can control TN-type (Twisted Nematic) or STN-type (Super Twisted Nematic) LCDs. The software configuration feature of the HT1650 make it suitable for multiple LCD applications including LCD modules and display subsystems. Only six lines (CS, WR, DB0~DB3) are required for the interface between the host controller and the HT1650.

Features
• Operating voltage: 2.7V~5.2V
• Built-in 32kHz RC oscillator
• External 32.768kHz crystal oscillator or 32kHz frequency source input
• Standby current: <1μ 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. of 64x32 patterns, 64 segments and 32 commons
• 80 segments and 16 commons selectable by command method
• Built-in bit-map display RAM: 2048 bits (=64x32 bits)
• Built-in internal resistor type bias generator
• Six-wire interface (four data wires)
• Eight kinds of time base or 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
• 128-pin QFP package

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