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¡ Semiconductor

MSM6775

PIN DESCRIPTIONS

Symbol

Type

OSC-IN

I

OSC-C

O

OSC-R

O

DATA

I

CLOCK

I

LOAD

I

BLANK

I

COM5

COM1 to

SEG80

SEG1 to

—

O

O

—

DSEL1

I

DSEL2

I

Pins for oscillation. The oscillator circuit is configured by externally connecting two

resistors and a capacitor. Make the wiring length as short as possible, because the

resistor connected to the OSC-IN pin has a higher value and the circuit is susceptible

to external noise.

Serial data input pin. The display goes on when input data is at "H" level, and it goes

off when input data is at "L" level.

Shift clock input pin. Data from the DATA pin is transferred in synchronization with the

rising edge of the shift clock. (Built-in Schmitt circuit is used.)

Load signal input pin. Serially input data is transferred to the 80-bit latch at "H" level

of this load signal, then held at "L" level.

Input pin that turns off all segments. The entire display goes off when "L" level is

applied to this pin. The display returns to the previous state when "H" level is applied.

Input pins to select 1/3, 1/4, or 1/5 duty. Following shows how each duty is selected.

DSEL2

DSEL1

L

L

L

H

H

X

Duty selected

1/3

1/4

1/5

X: Don't care

Display output pins for LCD. These pins are connected to the COMMON side on the

LCD panel.

Display output pins for LCD. These pins are connected to the SEGMENT side on the

LCD panel. For the correspondence between the output of these pins and input data,

see Section, "Data Structure".

Bias pins for LCD drive. Through these pins, bias voltages for the LCD

are externally supplied. The bias potential must meet the following condition:

Supply voltage pin and ground pin.

Description