Z89340 Datasheet, PDF (17/30 Pages) Zilog, Inc. – Digital Wavetable Engine

Z89340
Digital Wavetable Engine
ADPCM Oscillator
ROM. Also, the wavetable synthesis extensions of the
The ADPCM Oscillator works in much the same way as the
Sample Loop and Wavetable Oscillators. The main differ-
ences are that, due to the nature of ADPCM, the frequency
cannot be negative (you cannot with the Sample Loop Os-
cillator you can play a sound backwards, with Wavetable
Mode and ADPCM), and ADPCM will not allow playing a
sound faster than the sampling rate at which it is stored in
Wavetable Mode Oscillator are not available. The Z89340
handles IMA/DVI format ADPCM in 4- and 8-bit modes.
The ADPCM Oscillator provides a way to compact the da-
ta, but with some degree of sound degradation. However,
in many applications the trade-off may be worthwhile. (Re-
fer to Figure 11 for ADPCM-IMA/DVI Oscillator Address
Map).
1
Figure 11. The ADPCM-IMA/DVI Oscillator Address Map
DS96DSP0201
PRELIMINARY
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