DESCRIPTION

The SM3512 is a CMOS 4-bit single-chip microcomputer for databank incorporating data memory RAM, LCD driver, key/switch input circuit, 8-bit parallel I/O port, 2 output ports, external memory control circuit, and buzzer output circuit.

FEATURES

• ROM capacity :

Program ROM 8 k x 23 bits

Character ROM 5 x 9 x 128 bits

Constant ROM 208 x 4 bits

• RAM capacity :

Working RAM 256 x 4 bits

Display RAM 60 x 9 bits

Data RAM 8 k x 8 bits

• Memory expansion (external) : 8 k x 8 bits

• LCD display : 60-segment x 9-common

• I/O ports :

Parallel I/O 8 bits

Input 1 bit

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 :

System clock (built-in CR oscillator) 250 kHz

Timer (built-in CR oscillator) 32.8 kHz

(external crystal) 32.768 kHz

• Instruction cycle time : 12 µs

• Operating temperature : –10 to +60°C

• Supply voltage : 2.5 to 3.4 V

• Package : 100-pin QFP (QFP100-P-1420)