EE 451
Lab 5: Implementation of a Simple IIR Filter on the 56000

Start the difference equation

y(n) = x(n) + x(n-2) + 0.25 y(n-2)

The impulse response can be found by letting x(n) = delta(n):

h(n) = delta(n) + delta(n-2) + 0.25 h(n-2)

  1. Take the z-transform of the impulse response equation to find H(z).

  2. Find the frequency response H(w) of system by letting z = exp(j w).

  3. Plot the magnitude of H(w) vs. w and the phase of H(w) vs. w.

  4. Implement the difference equation on the 56002. Use the program from Lab 2 which reads data from the A/D and writes it to the D/A at 48 kHz. Between reading and writing the data, process it with the difference equation. On one channel of the D/A put out the processed data. On the other channel put out the unprocessed data.

  5. Use a 0.5 V P-P sine wave from your function generator. Measure and plot the amplitude and phase of the output from 100 Hz to 20 kHz. Compare to the plots of Part 4.

Bill Rison, < >
Tue Oct 1 1996
Copyright © 1996, New Mexico Tech