mcf51ac256a Freescale Semiconductor, Inc, mcf51ac256a Datasheet - Page 242

• Manufacturer Part Number: mcf51ac256a
• Description: Mcf51ac Flexis
• Manufacturer: Freescale Semiconductor, Inc

FlexTimer Module (FTMV1)
11.4.8
The combine mode is selected when:
In combine mode the channel (n) (an even channel) and channel (n+1) (the adjacent odd channel) are
combined to generate a PWM signal in the channel (n) output.
In the combine mode the PWM period is determined by (FTMxMODH:FTMxMODL -
FTMxCNTINH:FTMxCNTINL + 0x0001) and the PWM pulse width (duty cycle) is determined by
(|FTMxC(n+1)VH:FTMxC(n+1)VL - FTMxC(n)VH:FTMxC(n)VL|).
The TOF bit is set and the timer overflow interrupt is generated (if TOIE = 1) at the end of the PWM period
(when the FTM counter changes from FTMxMODH:FTMxMODL to FTMxCNTINH:FTMxCNTINL).
The CHnF bit is set and the channel (n) interrupt is generated (if CHnIE = 1) at the channel (n) match (FTM
counter = FTMxC(n)VH:FTMxC(n)VL). The CH(n+1)F bit is set and the channel (n+1) interrupt is
generated (if CH(n+1)IE = 1) at the channel (n+1) match (FTM counter =
FTMxC(n+1)VH:FTMxC(n+1)VL).
If (ELSnB:ELSnA = 1:0) then the channel (n) output is forced low at the beginning of the period (FTM
counter = FTMxCNTINH:FTMxCNTINL) and at the channel (n+1) match (FTM counter =
FTMxC(n+1)VH:FTMxC(n+1)VL). It is forced high at the channel (n) match (FTM counter =
FTMxC(n)VH:FTMxC(n)VL)(Figure
If (ELSnB:ELSnA = X:1) then the channel (n) output is forced high at the beginning of the period (FTM
counter = FTMxCNTINH:FTMxCNTINL) and at the channel (n+1) match (FTM counter =
FTMxC(n+1)VH:FTMxC(n+1)VL). It is forced low at the channel (n) match (FTM counter =
FTMxC(n)VH:FTMxC(n)VL)(Figure
In combine mode the ELS(n+1)B and ELS(n+1)A bits are not used in the generation of the channel (n) and
(n+1) output.
11-42
with ELSnB:ELSnA = X:1
with ELSnB:ELSnA = 1:0
channel (n+1) match
channel (n) output
channel (n) output
•
channel (n) match
FTM counter
(FTMEN = 1) and (COMBINE = 1) and (CPWMS = 0)
Combine mode
MCF51AC256 ColdFire Integrated Microcontroller Reference Manual, Rev. 5
Figure 11-44. Combine mode
11-44).
11-44).
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