Enhanced Modular Input/Output Subsystem (eMIOS)
MPC5565 Microcontroller Reference Manual, Rev. 1.0
16-74
Freescale Semiconductor
shows the operation of the OPWMB mode with the output disable signal asserted. The output
disable forces a transition in the output flip-flop to the EDPOL bit value. After the output disable is
negated, the output flip-flop is allowed to transition at the next A1 or B1 match. The output disable does
not modify the flag bit behavior. There is one system clock delay between the assertion of the output
disable signal and the transition of the output flip-flop.
Figure 16-55. eMIOS OPWMB Mode Example — Active Output Disable
shows a waveform changing from 100% to 0% duty cycle. In this case EDPOL is zero and
B1 is set to the same value as the period of the selected external time base.
Figure 16-56. eMIOS OPWMB Mode Example — 100% to 0% Duty Cycle
if B1 is set to a value lower than 0x000008 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 flip-flop
transitions to the compliment of EDPOL at B1 matches. In this example, if B1 = 0x000009, a B1 match
does not occur, and thus a 0% duty cycle signal is generated.
Cycle n
Cycle n+1
Cycle n+2
A1 value
B1 value
B2 value
0x000008
0x000002
0x000006
0x000008
0x000001
Selected
0x000004
0x000006
MODE[0] = 1
A2 value
0x000002
0x000004
0x000006
0x000002
0x000004
0x000006
0x000008
0x000006
Output flip-flop
Write to B2
Match A1
Match B1
Match B1
A1/B1
Due to B1 match
FLAG set event
cycle n-1
Time
Write to A2
Match A1
Write to A2
Match B1
load signal
counter bus
EDPOL = 0
0x000008
0x000007
0x000006
0x000005
0x000004
0x000003
0x000002
0x000001 0x000000
0%
100%
Selected
EDPOL = 0
A1 value
B1 value
Output flip-flop
0x000008
Prescaler = 1
Cycle 1
Cycle 2
Cycle 3
Cycle 4
Cycle 5
Cycle 6
Cycle 7
Cycle 8
Cycle 9
0x000007
0x000006
0x000005
0x000004
0x000003
0x000002
0x000001
0x000000
A2 value
Time
counter bus
Summary of Contents for MPC5565
Page 18: ...MPC5565 Microcontroller Reference Manual Devices Supported MPC5565 MPC5565 RM Rev 1 0 09 2007...
Page 34: ...MPC5565 Reference Manual Rev 1 0 Freescale Semiconductor 15...
Page 35: ...MPC5565 Reference Manual Rev 1 0 16 Freescale Semiconductor...
Page 553: ...Flash Memory MPC5565 Microcontroller Reference Manual Rev 1 0 13 38 Freescale Semiconductor...
Page 559: ...SRAM MPC5565 Microcontroller Reference Manual Rev 1 0 14 6 Freescale Semiconductor...
Page 973: ...Preface MPC5565 Microcontroller Reference Manual Rev 1 0 21 36 Freescale Semiconductor...
Page 1153: ...Calibration MPC5565 Microcontroller Reference Manual Rev 1 0 B 8 Freescale Semiconductor...