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etc. Contact SHARP in order to obtain the latest device specification sheets before using any SHARP device.

SM3518

DESCRIPTION

The SM3518 is a CMOS 4-bit single-chip micro-

computer for databank incorporating data memory

RAM, LCD driver (the output is adjustable in 16

steps for various contrast), key/switch input circuit,

8-bit parallel I/O port, 2 output ports and buzzer

output circuit. The chip also has memory expansion

controlling feature. One of two ports contains spe-

cial output circuit for infrared (IR) communication.

By connecting an external crystal, a 1 Hz timer is

made possible for easier clock function.

FEATURES

• ROM capacity :

Program ROM

12 k x 23 bits

Character ROM

6 x 8 x 256 bits

Constant ROM

1 k x 4 bits

• RAM capacity :

Working RAM

256 x 4 bits

Display RAM

74 x 16 bits

Data RAM

3 k x 8 bits

• Memory expansion (external) : 1M x 8 bits x 3

• LCD display : 74 - segment x 16 - common

• I/O ports :

Parallel I/O

8 bits

Input

2 bits

Output

2 bits

Buzzer output

1 bit (4 kHz)

Key input

6 bits

• Standby release : 2 events (2 Hz signal, key input)

• Built-in oscillator :

• Instruction cycle time : 3 µs

• Operating temperature : –10 to +60°C

• Supply voltage : 2.5 to 5.5 V

• Package : 128-pin QFP (QFP128-P-2828)

[Test Sample only]

SM3518

4-Bit Single-Chip Microcomputer

(For Data Bank Use)

System clock (built-in CR oscillator)

1 MHz

(external ceramic resonator)

1 MHz

Timer (built-in CR oscillator)

32.8 kHz

(external crystal)

32.768 kHz