MSM6789A Datasheet, PDF (1/53 Pages) OKI electronic componets – SBC Solid-State Recorder IC

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MSM6789A/6789L
SBC Solid-State Recorder IC
MSM6789A/6789L
GENERAL DESCRIPTION
The MSM6789A/6789L, an improved version of MSM6788, is a solid-state recorder developed using
the Sub Band Coding (SBC) method.
Just like MSM6788, the MSM6789A/6789L has a stand-alone mode and a microcontroller interface
mode. In the stand-alone mode, record/playback conditions can be selected from pins and the
MSM6789A/6789L can be controlled by a simple drive timing. In the microcontroller interface mode,
record/playback can be controlled by commands from the microcontroller, and more functions are
available than in the stand-alone mode.
The MSM6789A/6789L can directly drive serial voice ROM as external memory as well as serial
register or general-purpose DRAM* (1-bit ¥ or 4-bit ¥ type selectable) as external memories, which
allows a recording and playback circuit with fixed messages to be built easily. The method from
microcontroller is the same as the MSM6788.
* Only for MSM6789A
• Difference between MSM6788 and MSM6789A
MSM6788
MSM6789A
General DRAM
Unavailable
Available
Unvoiced-part elimination function No
Yes
PCM playback
No
Yes
• SBC method:
The SBC method divides voice frequencies into five bands and codes the component for each of
the bands separately, as shown below.
Gain
ch 1
ch 2
ch 3
@fs=8.0 Hz
ch 4
ch 5
0
1
2
3
kHz
f (Hz)
Note: Thisdatasheetexplainsastand-alonemodeandamicrocontrollerinterfacemode,separately.