2

BLOCK DIAGRAM

Liquid-crystal drive circuit

Selection control circuit

Bidirectional shift register

Level shifter

DIR

L1

L2

/DOFF’

STB

/FRM

Column driver interface

Remark

/xxx indicates active low signal.

BLOCK FUNCTION

1. Liquid-crystal drive circuit

This circuit selects and outputs the level for liquid-crystal driving.

2. Selection control circuit

This circuit creates the signal which will select the level of the output signal, based on the output of the shift

register circuit and the driving level power selection signals L1 and L2

3. Bidirectional shift register circuit

This refers to the 80-bit bidirectional shift register circuit. The DIR signal can be used to switch over the shift

direction.

The data that has been entered from the /FRM pin is shifted by the low drive signal strobe (STB).

4. Level shifter circuit

This circuit transforms the 5-V signals to the high-voltage signals for liquid-crystal driving.