Pulse-Width Modulator for Motor Control (PWMMC)
Output Control
If the OUTCTL bit is set, the PWM pins can be controlled by the OUTx bits. These
bits behave according to Table 12-6.
Table 12-6. OUTx Bits
OUTx Bit
Complementary Mode
1 — PWM1 is active.
Independent Mode
1 — PWM1 is active.
0 — PWM1 is inactive.
OUT1
0 — PWM1 is inactive.
1 — PWM2 is complement of PWM 1.
0 — PWM2 is inactive.
1 — PWM2 is active.
0 — PWM2 is inactive.
OUT2
OUT3
OUT4
OUT5
OUT6
1 — PWM3 is active.
0 — PWM3 is inactive.
1 — PWM3 is active.
0 — PWM3 is inactive.
1 — PWM4 is complement of PWM 3.
0 — PWM4 is inactive.
1 — PWM4 is active.
0 — PWM4 is inactive.
1 — PWM5 is active.
0 — PWM5 is inactive.
1 — PWM5 is active.
0 — PWM5 is inactive.
1 — PWM 6 is complement of PWM 5.
0 — PWM6 is inactive.
1 — PWM6 is active.
0 — PWM6 is inactive.
When OUTCTL is set, the polarity options TOPPOL and BOTPOL will still affect the
outputs. In addition, if complementary operation is in use, the PWM pairs will not
be allowed to be active simultaneously, and dead-time will still not be violated.
When OUTCTL is set and complementary operation is in use, the odd OUTx bits
are inputs to the dead-time generators as shown in Figure 12-15. Dead-time is
inserted whenever the odd OUTx bit toggles as shown in Figure 12-23. Although
dead-time is not inserted when the even OUTx bits change, there will be no
dead-time violation as shown in Figure 12-24.
Setting the OUTCTL bit does not disable the PWM generator and current sensing
circuitry. They continue to run, but are no longer controlling the output pins. In
addition, OUTCTL will control the PWM pins even when PWMEN = 0. When
OUTCTL is cleared, the outputs of the PWM generator become the inputs to the
dead-time and output circuitry at the beginning of the next PWM cycle.
NOTE:
To avoid an unexpected dead-time occurrence, it is recommended that the OUTx
bits be cleared prior to entering and prior to exiting individual PWM output control
mode.
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
MOTOROLA Pulse-Width Modulator for Motor Control (PWMMC)
Data Sheet
147
FREESCALE [ Freescale ]
