CS1621 is a multifunction storage mapping 128 dot matrix LCD driver circuit. CS1621 in the S / W structure characteristics, making it suitable for dot matrix LCD display, including LCD modules and display subsystems, CS1621B with power-saving features. 
 Features 

 Operating voltage: 2.4V ~ 5.2V 
 Internal 256KHz RC oscillator 
 32KHz 256KHz frequency crystal or external input 
 Optional 1 / 2 or 1 / 3 bias and 1 / 2, 1 / 3 or 1 / 4 duty LCD display 
 Internal time base frequency sources 
 Buzzer drive signal frequency may choose 2KHz or 4KHz 
 Power consumption can be reduced with the shutdown command 
 Internal time base generator and WDT Watchdog Timer 
 Internal time base or WDT overflow output 
 Eight time base / WDT clock source 
 32 × 4 LCD driver 
 Internal 32 × 4bit display RAM 
 Quad Serial Interface 
 Internal LCD driving frequency source 
 Command control operation available 
 Data mode and command mode instructions 
 R / W address auto-accumulation 
 Three data accessing modes 
 VLCD pin for adjusting LCD operating voltage