General Description
The HT1621 is a 128 pattern (324), memory mapping, and multi-function LCD driver. The S/W configuration
feature of the HT1621 makes it suitable for multiple LCD applications including LCD modules and display sub
systems. Only three or four lines are required for the in terface between the host controller and the HT1621.
The HT1621 contains a power down command to reduce power consumption.

FEATUREs
Operating voltage: 2.4V~5.2V
Built-in 256kHz RC oscillator
External 32.768kHz crystal or 256kHz frequency source input
Selection of 1/2or1/3 bias, and selection of 1/2 or 1/3 or 1/4 duty LCD applications
Internal time base frequency sources
Two selectable buzzer frequencies (2kHz/4kHz)
Power down command reduces power consumption
Built-in time base generator and WDT
Time base or WDT overflow output
8 kinds of time base/WDT clock sources
324 LCD driver
Built-in 324 bit display RAM
3-wire serial interface
Internal LCD driving frequency source
Software configuration feature
Data mode and command mode instructions
R/W address auto increment
Three data accessing modes
VLCD pin for adjusting LCD operating voltage
HT1621: 44-pin QFP/LQFP package
HT1621B: 48-pin SSOP/LQFP packages
HT1621G: Gold bumped chip