VS1103 datasheet(24/61 Pages) VLSI

24 / 61 page

VS1103b Datasheet

FUNCTIONAL DESCRIPTION

6.2.2

Supported MIDI Formats

General MIDI and SP-MIDI format 0 ﬁles are played. Format 1 and 2 ﬁles must be converted

to format 0 by the user. The maximum simultaneous polyphony is 40 (peak polyphony 64).

Actual polyphony depends on the internal clock rate (which is user-selectable), the instruments

used, and the possible postprocessing effects enabled, such as bass and treble enhancers.

The polyphony restriction algorithm makes use of the SP-MIDI MIP table, if present. MIDI

implements click-avoiding smooth note removal.

When run in Real Time RT-Midi mode without other signal paths, 36.86 MHz (3.0× input clock)

achieves 16-26 simultaneous sustained notes. The instantaneous amount of notes can be

larger. 36 MHz is a fair compromise between power consumption and quality, but higher clocks

can be used to increase polyphony. They are also needed if multiple signal paths are used.

Reverb effect can be controlled by the user. In addition to reverb automatic and reverb off

modes, 14 different decay times can be selected. These roughly correspond to different room

sizes. Also, each midi song decides how much effect each instrument gets. Because the reverb

effect uses about 4 MHz of processing power the automatic control enables reverb only when

the internal clock is at least 3.0×.

When EarSpeaker spatial processing is active, MIDI reverb is not used.

VS1103b supports unique instruments in the whole GM1 instrument set and one bank of GM2

percussions.

Version: 1.04, 2018-03-16

VS1103 Datasheet(PDF) 24 Page - VLSI Solution Oy