SM1125 series

SEIKO NPC CORPORATION —2

BLOCK DIAGRAM

PIN DESCRIPTION

Number

Name

I/O

Function

1

OSC

I

Built-in RC oscillator option: External resistor and capacitor connection pins

External clock input option: External reference clock input (gate circuit built-in)

2

SI

I

Playback control serial interface data input

3

SC

I

Playback control serial interface clock input

4

ST

I

Playback start/stop control signal input

5

TEST

I

Test input pin. Leave open or tie to VSS. (Pull-down resistance built-in)

6

MTO

O

Playback melody signal output

7

VDD

–

Supply pin (+)

8

VSS

–

Ground pin

Gate

1/2 or 1/4

SW2

Divider

1/128

Scale

Counter

Scale

ROM

Tempo Latch

Tempo Counter

Rhythm

Counter

Address

Counter

Start

Address

Latch

Main

ROM

Control

Circuit

OSC

SI

SC

ST

VSS

VDD

MTO

TEST

Multi-

Plexer

OSC

SW1

Master slice