mc68hc908mr8 Freescale Semiconductor, Inc, mc68hc908mr8 Datasheet - Page 161

• Manufacturer Part Number: mc68hc908mr8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

9.7 Fault Protection
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor
UP/DOWN COUNTER
PWM VALUE = 3
DEAD-TIME = 2
MODULUS = 4
PWM1/PWM2
DEAD-TIME
OUTCTL
PWM1
PWM2
OUT1
OUT2
Figure 9-20. Dead-Time Insertion During OUTCTL = 1
2
Conditions may arise in the external drive circuitry which require that the
PWM signals become inactive immediately, such as an overcurrent fault
condition. Furthermore, it may be desirable to selectively disable
PWM(s) solely with software.
One or more PWM pins can be disabled (forced to their inactive state)
by applying a logic high to either of the two external fault pins or by
writing a logic high to either of the disable bits (DISX and DISY in PWM
control register 1).
disabling scheme. While the PWM pins are disabled, they are forced to
their inactive state. The PWM generator continues to run — only the
output pins are disabled
Pulse-Width Modulator for Motor Control (PWMMC)
DEAD-TIME INSERTED BECAUSE
WHEN OUTCTL WAS SET, THE
STATE OF OUT1 WAS SUCH THAT
PWM1 WAS DIRECTED TO TOGGLE
2
Figure 9-21
Pulse-Width Modulator for Motor Control (PWMMC)
DEAD-TIMES INSERTED
BECAUSE OUT1 TOGGLES,
DIRECTING PWM1 TO
TOGGLE.
shows the structure of the PWM
2
2
NO DEAD-TIME INSERTED
BECAUSE OUT1 IS NOT
TOGGLING.
Fault Protection
Technical Data
161