Mon Jul 16 22:13:34 CEST 2007
filter bank on PIC18
so, if i want to run a digital filter on the PIC18, for, say, some
demodulation. what performance am i looking at?
running on 5V and a xtal, i can get to 10 MIPS. for audio rate
signals, say up to 5kHz, this gives 2000 instructions per
sample. that's not quite nothing.
using half of this for the filtering, and the other half for the
decoding and the actual application, we're looking at 1000
instructions of DSP to burn. looks to me there's plenty of room.
to make it sound good, tones need to be quite stable. at least 1/16th
of a second. say 6.4kHz, this is about 400 samples.