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Configurable Enhanced Modular IO Subsystem (eMIOS200)
MPC5644A Microcontroller Reference Manual, Rev. 6
682
Freescale Semiconductor
Figure 22-37. OPWMB mode with active output disable
shows a waveform changing from 100% to 0% duty cycle. EDPOL in this case is zero. In
this example B1 is programmed to the same value as the period of the external selected time base.
Figure 22-38. OPWMB mode from 100% to 0% duty cycle
if B1 is set to a value lower than 0x8 it is not possible to achieve 0% duty cycle by only
changing A1 register value. Since B1 matches have precedence over A1 matches the output pin transitions
to the opposite of EDPOL bit at B1 match. Note also that if B1 is set to 0x9, for instance, B1 match does
not occur, thus a 0% duty cycle signal is generated.
22.5.1.2
Input programmable filter (IPF)
The IPF ensures that only valid input pin transitions are received by the channel edge detector. A block
diagram of the IPF is shown in
EDPOL = 0
cycle n
cycle n+1
cycle n+2
A1 value
B1 value
B2 value
0x000008
0x000002
0x000006
0x000008
0x000001
Selected
0x000004
0x000006
MODE[6] = 1
A2 value 0x000002
0x000004
0x000006
0x000002
0x000004
0x000006
0x000008
0x000006
Output pin
write to B2
write to A2
write to A2
Match A1
Match A1
Match B1
Match B1
Match B1
due to B1 match cycle n-1
FLAG set event
Output Disable
Counter Bus
FLAG pin/register
FLAG clear
0x000008 0x000007 0x000006 0x000005 0x000004 0x000003 0x000002 0x000001 0x000000
0%
100%
Selected
EDPOL = 0
A1 value
B1 value
Output pin
0x000008
Prescaler = 1
cycle 1
cycle 2
cycle 3
cycle 4
cycle 5
cycle 6
cycle 7
cycle 8
cycle 9
counter bus
0x000007 0x000006 0x000005 0x000004 0x000003 0x000002 0x000001 0x000000
A2 value
Summary of Contents for MPC5644A
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Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...