SM1124 Series

NIPPON PRECISION CIRCUITS—5

Input during playback mode only

Input during non-playback mode

Playback control

The ST pin controls the start of playback. While ST

is HIGH (VDD), the tune is played repeatedly, and

when ST goes LOW (VSS), playback stops. Tunes

are selected by the input serial data on pins SI and

ST

CLK

ST

CLK

SC. The final 4 bits form the valid selection data, and

this data is retained even after playback.

If serial data is input during playback, the SM1124

ignores this data and playback continues.

* Pin SC should be LOW when either a LOW-to-HIGH or HIGH-to-LOW transition occurs on pin ST.

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SI

SC

ST

MTO

B3 B2 B1 B0

Invalid

Data

Valid

Data

Invalid

Data

B 3

B 2

B 1

B 0

S T

Music selection

LLLL

L

→ H

1st tune

LLL

H

L

→ H

2nd tune

LL

H

L

L

→ H

3rd tune

LL

H

H

L

→ H

4th tune

LH

L

L

L

→ H

5th tune

LH

LH

L

→ H

6th tune

LH

H

L

L

→ H

7th tune

L

HHH

L

→ H

8th tune

1. H = VDD level, L = VSS level

H

LLL

L

→ H

9th tune

HL

L

H

L

→ H

10th tune

HL

HL

L

→ H

11th tune

HL

H

H

L

→ H

12th tune

HH

L

L

L

→ H

13th tune

HH

L

H

L

→ H

14th tune

HHH

L

L

→ H

15th tune

HHHH

L

→ H

16th tune

B 3

B 2

B 1

B 0

S T

Music selection