The MA-1 was the first SMAF-compatible audio LSI to be released by Yamaha. It boasts a number of impressive features which make it highly suitable for use in mobile phones.
The MA-1's built-in FM sound generator can generate 128 different tones (the 128 instruments specified by the General MIDI standard). FM yields high sound quality, and since there are no limitations on the tones which can be generated, the MA-1 can be used to generate a huge variety of different sounds.
Although potentially a rich diversity of sounds can be generated, since FM sound parameters can be specified using just a few bytes, playback data for the MA-1 is highly compact.
The MA-1 boasts 4-note polyphony. This feature can be used either to create 4-note harmonies or to play notes with 4 different timbres.
The MA-1 incorporates a built-in hardware sequencer which can reproduce music data with little CPU overhead. Also, since the data for playback is transferred from the mobile phone's internal memory via a serial link, there is no limitation on the amount of data which can be stored for playback.
The MA-1 includes a built-in amplifier for driving dynamic speakers which delivers an output power level of 300 mW. The chip also includes a built-in equalizer circuit which compensates for the frequency characteristics of a speaker or handset. Despite these advanced features, the MA-1 is contained in a miniature package, allowing its easy incorporation into the design of a mobile device.
FM sound generator
Polyphony: 4-note polyphony
(4 independent sounds can be generated simultaneously.)
Equalizer circuit to optimize frequency characteristics of sound for speakers
Current drawn in Standby mode: less than 1 A (typically)