¡ Semiconductor

MSM6786

7/17

FEDL6786-03

FUNCTIONAL DESCRIPTION

Pin Functional Description

OSC (Pin 50)

This is an input/output pin for the oscillator to generate LCD AC lighting and keyscan pulses.

Connect an external capacitor and resistor as shown below to form an RC oscillation circuit.

DATA I/O (Pin 44)

This is a serial data input/output pin. The pin is in output state from the first shift clock rise after

key data output command writing, to the load pulse rise, and in input state otherwise. (The

pin is in input state during reset.)

The relationship between the data levels of this pin and the operations is shown below.

Level

Display

Key Status

"H"

ON

ON (close)

"L"

OFF

OFF (open)

CLOCK (Pin 43)

This is an input pin for the shift clock. DATA I/O pin data is either input or output in

synchroniza-tion with each rising clock edge.

LOAD (Pin 42)

This is a load pulse input pin used to transfer serial input data to a latch for display, to write

commands, or to release the DATA I/O pin in output state.

OSC