YMU759 Datasheet, PDF (6/18 Pages) List of Unclassifed Manufacturers – SYNTHESIS LSI FOR PORTABLE TELEPHONE

YMU759
Outline of blocks
Explanation about outline of built-in each blocks and flow of the signal are follows.
Register
FIFO
Clock
Generate
Hardware
Sequencer
FM
Sound
Generator
ADPCM
Playback
Headphone
Output
DAC
EQ
Amplifier
External
Parts
Speaker
Amplifier
CPU interface
Receives commands send from external CPU, interprets the contents, and then writes them into registers by index
address. Controls reading of designated register data.
As interfaces for controlling YMU759, 4 wire serial and 12 wire parallel interfaces are provided, which can be
selected through IFSEL terminal.
Registers
Register groups that control the LSI except for sequence data.
FM tone register data, various volumes and other control data are store here.
FIFO
Sequence data to move hardware sequencer and ADPCM wave data are stored in FIFO.
This device is equipped with four FIFOs for FM and two FIFOs for ADPCM.
The FIFOs for FM stores sequence data and those for ADPCM stores sequence and waveform data. The size of
FIFOs for FM is 96 bytes, the one for ADPCM data is 384 bytes, and the one for sequence data is 32 bytes.
Hardware sequencer
FIFO is provided as a previous stage of the sequencer which reads sequence data from FIFO to control FM and
ADPCM sections.
The sequence data are compatible with SMAF(Synthetic music Mobile Application Format) proposed by yamaha.
FM synthesis
This is a synthesis that uses Yamaha’s original FM system. It is able to generate up to 16 voices simultaneously.
This section plays in accordance with commands from the sequencer.
It can also play by directly controlling various registers without using the sequencer.
The sampling frequency is 49.7 kHz that complies with stereophonic sound.
ADPCM playback
This section decodes 4 bit ADPCM data to 16 bit data by using the sampling frequency of 4 kHz or 8 kHz.
It can playback one voice. It playback according to command from sequencer.
And it can playback to control various register directly without using sequencer.
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