Enhanced Modular Input/Output Subsystem (eMIOS)
MPC5565 Microcontroller Reference Manual, Rev. 1.0
Freescale Semiconductor
16-69
If FORCMB is set, the output flip-flop value depends on the selected dead time insertion mode. In leading
dead time insertion mode, FORCMB sets the output flip-flop to the value of EDPOL. In trailing dead time
insertion mode, the output flip-flop is forced to the compliment of EDPOL.
NOTE
Setting the FORCMA bit does not reset the internal time base to 0x000001
as a regular A1 match does. FORCMA and FORCMB have the same
behavior even in freeze or normal mode regarding the output flip-flop
transition.
The FLAG bit is not set in the case of the FORCMA, FORCMB or both bits being set at the same time.
When FORCMA and FORCMB are both set, the output flip-flop is set to the compliment of the EDPOL
bit. This is equivalent to FORCMA having precedence over FORCMB when lead dead time insertion is
selected and FORCMB having precedence over FORCMA when trailing dead time insertion is selected.
Duty cycles from 0% to 100% can be generated by setting appropriate A1 and B1 values relative to the
period of the external time base. Setting A1 = 1 or A1 = 0 generates a 100% duty cycle waveform. If
A1 > period ÷ 2, where period refers to the selected counter bus period, then a 0% duty cycle is produced.
Assuming EDPOL is one and OPWMCB mode with trailing dead time insertion mode is selected, 100%
duty cycle signals can be generated if B1 occurs at or after the cycle boundary (external counter = 1).
NOTE
A special case occurs when A1 is set to the external counter bus period ÷ 2,
which is the maximum value of the external counter. In this case the output
flip-flop is constantly set to the EDPOL bit value.
Internal channel logic prevents matches from one cycle to propagate to the next cycle. In trailing dead time
insertion mode, a B1 match from cycle (
n
) could eventually cross the cycle boundary and occur in cycle
(n+1). In this case the B1 match is masked out and does not cause the output flip-flop to transition.
Therefore matches in cycle (n+1) are not affected by the late B1 matches from cycle (
n
).
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...
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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...