YMU759
MA-2
Outline
YMU759 is a synthesis LSI for portable telephone that is capable of playing high quality music by utilizing
FMsynthesizer and ADPCM decorder that are included in this device. As a synthesis, YMU759 is equipped
with Yamaha’s original FM synthesizer, with which the device is capable of simultaneously generating up to
16 voices with different tones. Since the device is capable of generating ADPCM data simultaneously
synchronous with the play of the FM synthesizer, various sampled voices can be used as sound effects.
Since the play data of YMU759 are interpreted at anytime through FIFO, the length of the data (playing period)
is not limited, so the device can flexibly support applications such as incoming call melody distribution service.
The hardware sequencer built in this device allows playing of complex music without giving excessive load to
the CPU of the portable telephones. Moreover, the registers of the FM synthesizer can be operated directly for
real time sound generation, allowing, for example, utilization of various sound effects when using the game
software installed in the portable telephone.
YMU759 includes a speaker amplifier with low ripple whose maximum output is 550 mW
(SPVDD=3.6V). The device is also equipped with conventional functions including a vibrator and a circuit for
controlling LEDs synchronous with music.
For the headphone, it is provided with a stereophonic analog output terminal.
For the purpose of enabling YMU759 to demonstrate its full capabilities, Yamaha proposes to use “SMAF:
Synthetic music Mobile Application Format” as a data distribution format that is compatible with multimedia.
Since the SMAF takes a structure that sets importance on the synchronization between sound and images,
various contents can be written into it including incoming call melody with words that can be used for training
karaoke, and commercial channel that combines texts, images and sounds, and others. The hardware sequencer of
YMU759 directly interprets and plays blocks relevant to systhesis (playing music and reproducing ADPCM with FM
synthesizer) that are included in the data distributed in SMAF.
Features
FM synthesizer functions
Tones
FM synthesizer is capable of creating countless tones theoretically.
When synthesizing tones, it is necessary to designate the number of operators to be used for the synthesis.
(Refer to “5-7. FM synthesis section” for explanation of operator.)
Increasing the number of operators allows synthesis of tones that are more intricate and closer to those
generated by natural musical instruments.
YMU759 supports synthesis of tones of two types including 2-operator tones and 4-operator tones.
Because operator's wave shape can be chosen from eight kinds, the quality of sound improves more
remarkably than 2 operator sound of the MA-1 series. (A MA-1 series can choose operator wave shape from
two kinds.)
Number of voices simultaneously generated
YMU759 is equipped with 32 operators.
The number of voices simultaneously generated varies depending on how many 2-operator tones and
4-operator tones are used.
YAMAHA CORPORATION
YMU759 CATALOG
CATALOG No.:LSI-4MU759A2
2001.1
ETC [ ETC ]
