YMF781 Datasheet, PDF (5/14 Pages) YAMAHA CORPORATION – APL-1 Automobile sound PLayer-1

YMF781
■Overview of the Operation
APL-1 includes the Synthesizer Core, the CPU for control and its peripheral circuit.
The CPU controls most of the controls such as Synthesizer Core and Input/Output Port.
Since the Synthesizer Core controls are all controlled by the built-in CPU, sound contents can be played by a simple
command from the external.
The sound contents are stored in the external ROM.
Since the sound contents support formats in SMAF, SMAF/Phrase and SMAF/Audio, ROM data can be created by the
development tool dedicated for APL-1.
The firmware in the built-in CPU is stored in the external ROM and can be updated by the exchange of ROM, or by
the download via the APL-1 Control Interface.
Likewise, for the sound contents, it can be updated by the exchange of ROM, or by the download via the APL-1
Control Interface.
APL-1 Control Interface: Clock Sync Serial, Asynchronous Serial (UART), is incorporated and can be selected by the
terminal. (Mode 1)
Mobile phone
PC
Memory card
Wireless communication
Sound Contents
Built-in CPU firmware
Flash-ROM
or ROM
Sound Contents
APL-1
Interface
Device
UART
Synthesizer
+
Clock
Control CPU
Core
Sync Serial
Host CPU
（MA-5）
Note: A configuration diagram, which mode 1 is selected as an APL-1 Control Interface, is shown.
Speaker
Output
AMP
Line out
The download of the sound contents and the update of the APL-1 firmware are normally performed via the host CPU.
When it is difficult to mount a download function in host CPU, the download of sound contents and the update of the
firmware can be performed directly by using the asynchronous serial (UART). However, the connection destination is
restricted to PC Asynchronous Serial (UART).
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