msm9811 Oki Semiconductor, msm9811 Datasheet - Page 31

• Manufacturer Part Number: msm9811
• Description: 4-channel Mixing Oki Adpcm Type Voice Synthesis Lsi
• Manufacturer: Oki Semiconductor

OPT Command
The OPT command changes the setting inside the LSI according to data stored in the TMP register. Table 4 shows
the correspondence between data input (D7 to D0) and options.
(Note) x indicates that data is independent of a function described.
When the OPT command is input, the LSI changes the option at the rising edge of the WR pulse. When power is
turned on, or when the RESET pulse is input, the registers corresponding to D4-D0 have been set to “L”.
If the option is changed when voice synthesis is in execution, voice quality may change. Oki recommends to set the
option after power is turned on or after RESET is input.
1)
Volume can be set by the CVOL command and PAN command, but a waveform may be clamped when channel
synthesis is executed.
If the CVOL command and PAN command are used to prevent a waveform from being clamped, the number of
steps used for actual volume decreases, and effective voice synthesis may not be performed.
If it is known that a waveform will be clamped, this option can set the volume of all channels to low, so that the
number of steps of the volume can be utilized to the maximum level.
2)
This LSI has a built-in oversampling circuit for digital filter processing. This oversampling system evenly
generates four times more points of sampling frequencies.
When power is turned on or if the RESET pulse is input, those pulses have been set to pass through the
oversampling circuit. If digital filter processing is unnecessary, change this setting by the OPT command.
OKI Semiconductor
Default
*
*
*
Volume Option
Digital Filter Processing
O4
0
0
1
1
x
x
x
x
x
O3
0
1
0
1
x
x
x
x
x
O2
x
x
x
x
0
0
1
x
x
O1
0
1
x
x
x
x
x
x
x
Table 4 OPT Command List
O0
0
1
x
x
x
x
x
x
x
Sets the volumes of all channels to V
Sets the volumes of all channels to 1/2 V
Sets the volumes of all channels to 1/4 V
Sets the volumes of all channels to 1/8 V
Secondary digital filtering is performed.
Primary digital filtering is performed.
An on-chip digital filter is not used.
Data is output directly from a D/A converter. (Output Z ≅ 3 k Ω )
Data is output via a voltage follower. (Output Z ≅ 500 Ω )
Description
DD
(p-p).
DD
DD
DD
(p-p).
(p-p).
(p-p).
FEDL9811FULL-04
MSM9811
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