Lab 5:

Lab 5 will use the timer/counters to create a siren 
sound through the speaker. This is the American version
that rises then falls in frequency continuously, not
the European one that is essentially two tones.

TCD0 will create the different frequencies in the siren tone
TCC0 will interrupt to update the tone
TCD1 will create a PWM signal that is filtered to control the volume

Use iox16a4u.h extensively. Do not use code like: 
  Reg = (1 << 4); 

Testing:
  *Siren sound should sound very much like what you normally hear. 
  *There should be no skipping or popping of the sound. It should 
   sound pretty smooth and clear.
  *In addition, you will demonstrate functionality and code either 
   in person in the lab.

Turn into COE TEACH: 
  A single file submitted with the linux tar command that contains
  a copy of your lab5.c code

Grading:
  *Circuit function                   +80% (demo system in lab)
    -performs as expected
    -if sound jumps, pops, etc.       -deduct 20%
    -other abnormality                -deduct  5% (for each distinct problem)
  *Documentation                      +20%
    -code well written, commented
    -poorly commented code            -deduct 15%

Lab Weighting is 0.20.