Commodore Amiga A1000, Hardware Reference Manual

Page: 148 / 380

NOTE
The Clock Interval is derived from the clock constant, where:
1
clock interval = --------------
clock constant
then scale the result to microseconds. In all of these calculations "ticks" and "timing
intervals" refer to the same thing.
SPECIFYING THE PERIOD VALUE
After you have selected the desired interval between data samples, you can calculate the
value to place in the period register by using the period formula:
desired interval clock constant
Period value = ---------------- = ------------------
clock interval samples per second
As an example, say you wanted to produce a 1 KHz sine wave, using a Table of eight data
samples (four data words) (see Figure 5-3).
Figure 5-3: Example Sine Wave
- Audio Hardware 139 -