mc9s08qg8 Freescale Semiconductor, Inc, mc9s08qg8 Datasheet - Page 241

• Manufacturer Part Number: mc9s08qg8
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

16.5.3
The meaning of channel interrupts depends on the current mode of the channel (input capture, output
compare, edge-aligned PWM, or center-aligned PWM).
When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select rising
edges, falling edges, any edge, or no edge (off) as the edge that triggers an input capture event. When the
selected edge is detected, the interrupt flag is set. The flag is cleared by the 2-step sequence described in
Section 16.5.1, “Clearing Timer Interrupt
When a channel is configured as an output compare channel, the interrupt flag is set each time the main
timer counter matches the 16-bit value in the channel value register. The flag is cleared by the 2-step
sequence described in
16.5.4
For channels that are configured for PWM operation, there are two possibilities:
The flag is cleared by the 2-step sequence described in
Freescale Semiconductor
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When the channel is configured for edge-aligned PWM, the channel flag is set when the timer
counter matches the channel value register that marks the end of the active duty cycle period.
When the channel is configured for center-aligned PWM, the timer count matches the channel
value register twice during each PWM cycle. In this CPWM case, the channel flag is set at the start
and at the end of the active duty cycle, which are the times when the timer counter matches the
channel value register.
Channel Event Interrupt Description
PWM End-of-Duty-Cycle Events
Section 16.5.1, “Clearing Timer Interrupt
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 1.01
Flags.”
Section 16.5.1, “Clearing Timer Interrupt
Flags.”
Timer/PWM (S08TPMV2)
Flags.”
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