Center for New Music and Audio Technologies

Conclusion

FPGAs provide an ideal environment for designing and emulating digital functions. The design CORDIC-based Oscillator had been successfully implemented and tested under real, performance like conditions.

The CORDIC algorithm is an iterative method to perform rotation, and therefore to compute sine values. This makes the CORDIC not the fastest method for calculating a sine function. However, the possibility of combining multiplication and sine computation in CORDIC makes the CORDIC-based oscillator an attractive solution since it saves the resources needed by a multiplier.

Clearly, many oscillators are necessary to perform additive synthesis. For 32-note polyphony (or timbre), with 64 partial components per note, a engine will need to generate 2,048 sine waves in total. This clearly exceeds the capacity of the prototyping environment used but high density devices provide sufficient resources for an additive synthesizer. Steadily increasing frequency rates for modern chip technologies, which make computing a desired value faster than accessing a lookup table, add another interesting aspect to the decision of what oscillator architecture to use.

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