SM1124 Datasheet, PDF (5/10 Pages) Nippon Precision Circuits Inc – Multimelody IC for Pagers

Input during playback mode only
SM1124 Series
ST
CLK
Input during non-playback mode
ST
CLK
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
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.
Invalid
Data
Valid
Data
Invalid
Data
SI
B3 B2 B1 B0
SC
ST
MTO
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
* Pin SC should be LOW when either a LOW-to-HIGH or HIGH-to-LOW transition occurs on pin ST.
Serial data selection¹
B3 B2 B1 B0
ST
Music selection
L
L
L
L
L→H
1st tune
L
L
L
H
L→H
2nd tune
L
L
H
L
L→H
3rd tune
L
L
H
H
L→H
4th tune
L
H
L
L
L→H
5th tune
L
H
L
H
L→H
6th tune
L
H
H
L
L→H
7th tune
L
H
H
H
L→H
8th tune
B3 B2 B1 B0
H
L
L
L
H
L
L
H
H
L
H
L
H
L
H
H
H
H
L
L
H
H
L
H
H
H
H
L
H
H
H
H
1. H = VDD level, L = VSS level
ST
L→H
L→H
L→H
L→H
L→H
L→H
L→H
L→H
Music selection
9th tune
10th tune
11th tune
12th tune
13th tune
14th tune
15th tune
16th tune
NIPPON PRECISION CIRCUITS—5