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MSM6502B/6512

¡ Semiconductor

LCD Drive Pins

SEG 0 to 26

COM 1 to 4

A special AC waveform designed to comply with liquid-crystal properties is

required for liquid-crystal-drive purposes. The MSM6502B/6512 is equipped with

a 1/4 duty, 1/3 bias liquid-crystal-drive circuit with four common output ports and

27 segments, to enable displays of up to 108 picture elements. On/off selection of

picture elements involves writing "0" or "1" to the corresponding bits in

the RAM 00H to 1AH display area, and subsequent automatic hardware

controlled display. The frame frequency is 64 Hz.

BZ/BZ

BZ and BZ are used in the generation of alarms and other sounds. The selectable

frequencies include three hardware frequencies (TBC output) of 512, 1024, and

2048 Hz, and a software type based on P5.0 data. These frequencies are selected

at P3. When one of the hardware frequencies is selected by P3, output of that

frequency is continuous. But selection of the software type results in output of the

P5.0 contents to generate a melody by program.

Symbol

Description

29 to 48

50 to 56

25 to 28

13,14

Pin

PIN DESCRIPTIONS (Continued)