MC68HC908LB8_05 Datasheet, PDF (102/234 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

High Resolution PWM (HRP)
TOP IN
BOT IN
TOP OUT
DT[7:0]
BOT OUT
DT[7:0]
Figure 10-7. Deadtime Insertion Waveforms
NOTE
Care must be taken when setting the duty cycle and deadtime values to
ensure that a PWM signal appears on both TOP and BOT when using the
module to control a half bridge. It is possible to configure the HRP to output
a continuous logic 0 on TOP or BOT.
If the deadtime is equal to or greater than the duty cycle value, the BOT
output will will remain at logic 0, while TOP will output a PWM signal. (See
Figure 10-8.) The duty cycle refers to the high level on BOT.
Similarly, if the deadtime is equal to or greater than the period minus the
duty cycle value, the TOP output will remain at logic 0, while BOT will output
a PWM signal. (See Figure 10-9.)
MC68HC908LB8 Data Sheet, Rev. 1
102
Freescale Semiconductor