sm1350 Nippon Precision Circuits Inc, (NPC), sm1350 Datasheet - Page 8

• Manufacturer Part Number: sm1350
• Description: High Tone Quality Melody Lsi
• Manufacturer: Nippon Precision Circuits Inc, (NPC)

FUNCTIONAL DESCRIPTION
Chattering Prevention
STN, STOP chattering prevention function
Standby Mode
The oscillator starts when STN goes from HIGH to LOW in standby mode. Input data is received and melody
data output starts 81.9 ms after the oscillator starts if STN is LOW.
Oscillator starts running
After the oscillator starts running, input data is considered valid 81.9 ms after STN and STOP have last
changed state. Input data is considered invalid for intervals less than 65.5 ms.
Reception
Reception
Internal
Input
Internal
STN or
Input
Clock
Melody
Output
Clock
STOP
OSC
STN
Figure 2. STN, STOP chattering prevention timing (oscillator running)
Figure 1. STN, STOP chattering prevention timing (standby mode)
Note: Refer to the "TIMING DIAGRAMS" section to confirm melody timing specifics.
Note: Refer to the "TIMING DIAGRAMS" section to confirm melody timing specifics.
81.9ms
65.5ms
SM1350 series
81.9ms
81.9ms
NIPPON PRECISION CIRCUITS INC.—8