ml2240 Oki Semiconductor, ml2240 Datasheet - Page 19

• Manufacturer Part Number: ml2240
• Description: 4-channel Mixing Oki Adpcm Algorithm-based Speech Synthesis Lsi
• Manufacturer: Oki Semiconductor

Mixing Function
The ML2240 can perform simultaneous mixing of 4 channels. It is possible to specify PLAY and STOP for each
channel separately.
• Precautions for Waveform Clamp at the Time of Channels Mixing
• Mixing of Different Sampling Frequency
Figures below show a case when a sampling frequency group played back a different sampling frequency group.
OKI Semiconductor
Figure 2 In Case a Different Sampling Frequency Played Back after the End of the Other Channel
When mixing of channels is done, the clamp occurrence possibility increases from the mixing calculation point
of view. If it is known beforehand that the clamp will occur, then adjust the sound volume by VOL command.
It is not possible to perform analog mixing by a different sampling frequency.
When performing analog mixing, the sampling frequency group of the first playback channel is selected.
Therefore, please note that if analog mixing is performed by a sampling frequency group other than the selected
sampling frequency group, then the playback will not be of constant speed: some times faster and at other times
slower.
The available sampling groups for analog mixing by a different sampling frequency are listed below.
Figure 1 In Case a Different Sampling Frequency Played Back during Playback of the Other
4.0 kHz, 8.0 kHz, 16.0 kHz, 32.0 kHz
5.3 kHz, 10.6 kHz, 21.3 kHz, 42.7 kHz
6.4 kHz, 12.8 kHz, 25.6 kHz
Channel 1
Channel 2
Channel 1
Channel 2
fs = 25.6 kHz (Invalid. Played back as fs = 32.0 kHz.)
fs = 16.0 kHz
fs = 16.0 kHz
End of channel 1
Channel Playback
··· (Group 1)
··· (Group 2)
··· (Group 3)
Normal playback if not played back by
other channel.
fs = 25.6 kHz (Valid)
FEDL2240DIGEST-02
ML2240 Family
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