Lostgallifreyan wrote:
An off-topic question, but very interesting at least to me... Do DDS chips
exist with 128 or even 256 phase accumulators onboard with the step size
adjustment being capable of matching the speed of the stepping itself
(though taking external control of local phase modulations between
accumulators), and allowing mixing of all outputs, perhaps in user-selected
groups based on binary fractions of the total accumulator count?

I ask because if they do it might be possible for me to convert my phase mod
synth code to dedicated hardware without resorting to very fast CPU's...
While the rates are audio only, the huge parallel array gets demanding of CPU
time as it is.

I suspect the answer to all that may be 'no' without custom VLSI chips
because of the relatively complex paths between accumulators needed for a
phase mod synth of N operators per algorithm, but maybe DDS chips come in
enough varieties to surprise me.

You can do this with an FPGA. That is a programmable VLSI chip that
you program yourself to perform the functions you need. It operates
at logic speed, not at processor speed.