Datasheet

113
7734Q–AVR–02/12
AT90PWM81/161
Table 12-6. Distribution of f
b2
in the modulated frame.
While ‘X’ in the table, f
b2
prime to f
b1
in cycle corresponding cycle.
So for each row, a number of fb2 take place of fb1.
Figure 12-12. Resulting frequency versus d.
12.7.2 Modes of Operation
12.7.2.1 Normal Mode
The simplest mode of operation is the normal mode. See Figure 12-6 on page 106.
The active time of PSCOUTn0 is given by the OT0 value. The active time of PSCOUTn1 is given
by the OT1 value. Both of them are 12 bit values. Thanks to DT0 & DT1 to adjust the dead time
between PSCOUTn0 and PSCOUTn1 active signals.
Distribution of fb2 in the modulated frame
PWM - cycle
Fractional
divider (d)
0123456789101112131415
0
1X
2X X
3XXX
4XXXX
5XXXXX
6 XXX XXX
7 XXXXXXX
8 XXXXXXXX
9 XXXXXXXXX
10 XXXXXXXXXX
11 XXX XXX XXX X X
12 XXX XXX XXX XXX
13 XXXXXXX XXX XXX
14 XXXXXXX XXXXXXX
15 XXXXXXXXXXXXXXX
f
b1
f
b2
d: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
f
OP