Bits
Function
15
- 7 Not used
6 - 0 Volume information, V6 -
VO
To
modulate only the frequency, you must attach a channel as a period modulator.
Define the modulator channel's
data
set
as a series of words, each containing period
information in the following format:
Bits
Function
15
- 0 Period information,
PIS
-
PO
If
you
want
to
modulate both period and volume on the same
channe~,
you need
to
attach the channel as both a period and volume modulator.
For
instance, if channel 0
is
used
to
modulate both the period and frequency of
channell,
you set two attach
bits-
bit
0
to
modulate the volume and bit 4
to
modulate the period. When period and
volume are both modulated, words
in
the modulator channel's
data
set are defined alter-
nately as volume and period information.
The
sample set of
data
in table 5-4 shows the differences in interpretation of
data
when
a channel is used directly for audio, when it is attached as volume modulator, when
it
is
attached as a period modulator, and when
it
is attached as a modulator of both volume
and period.
Table
5-4:
Data
Interpretation
in
Attach Mode
Independent
Modulating
Data
(not
Both
Modulating
Modulating
Words
Modulating)
Period
and
Volume
Period
Only
Volume
Only
Word I
I
data
I
data
I
I
volume for other channel I
I
period I
I
volume I
Word 2
I
data
I
data
I I period for other channel I
I
period I
I
volume I
Word 3
I
data
I
data
I I volume for other channel I
I
period I
I
volume I
Word 4
I
data
I
data
I I period for other channel I
I
period I
I
volume I
150 Audio Hardware
To Next Page
Loading...
