Freescale Semiconductor MC68HC908MR32 - Manual (Page 126)

Pulse-Width Modulator for Motor Control (PWMMC)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
126 Freescale Semiconductor
12.5 Output Control
This subsection discusses output control.
12.5.1 Selecting Six Independent PWMs or Three Complementary PWM Pairs
The PWM outputs can be configured as six independent PWM channels or three complementary channel
pairs. The option INDEP determines which mode is used (see
5.2 Functional Description ). If
complementary operation is chosen, the PWM pins are paired as shown in Figure 12-12 . Operation of
one pair is then determined by one PWM value register. This type of operation is meant for use in motor
drive circuits such as the one in
Figure 12-13 .
Figure 12-12. Complementary Pairing
Figure 12-13. Typical AC Motor Drive
PWM VALUE REGISTER
PWMS 1 AND 2
PWMS 3 AND 4
PWMS 5 AND 6
O
U
T
P
UT
CO
N
T
R
O
L
PWM VALUE REGISTER
PWM VALUE REGISTER
PWM1 PIN
PWM2 PIN
PWM3 PIN
PWM4 PIN
PWM5 PIN
PWM6 PIN
POLARITY & DEAD-TIME
INSERT
ION
PWM
1
PWM
2
PWM
3
PWM
4
PWM
5
PWM
6
AC
TO
MOTOR
INPUTS