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Enhanced Modular Input/Output Subsystem (eMIOS200)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
28-49
The FLAG bit is not set either in case of a FORCMA or FORCMB or even if both forces are issued at the
same time.
NOTE
FORCMA and FORCMB have the same behavior even in freeze or normal
mode regarding the output pin transition.
When FORCMA is issued along with
FORCMB, the output flip-flop is set to the opposite of EDPOL bit
value. This is equivalent of saying that
FORCMA
has precedence over FORCMB when lead dead-time
insertion is selected and FORCMB
has precedence over
FORCMA when trail dead-time insertion is
selected.
Duty cycle from 0% to 100% can be generated by setting appropriate values to A1 and B1 registers
relatively to the period of the external time base. Setting A1 = 1 generates a 100% duty cycle waveform.
If A1 is greater than the maximum value of the selected counter bus period, then a 0% duty cycle is
produced. Assuming EDPOL is set to one and OPWMCB mode with trail dead-time insertion, 100% duty
cycle signals can be generated if B1 occurs at or after the cycle boundary (external counter = 1).
Only values different than 0x00_0000 are allowed to be written to A1 register. If 0x00_0000 is loaded to
A1 the results are unpredictable.
NOTE
A special case occurs when A1 is set to (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.
The internal channel logic prevents matches from one cycle to propagate to the next cycle. In trail
dead-time insertion B1 match from cycle (
n
) could eventually cross the cycle boundary and occur in cycle
(
n
+ 1). In this case 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
).
shows a 100% duty cycle output signal generated by setting A1 = 4 and B1 = 3. In this case
the trailing edge is positioned at the boundary of cycle
n
+ 1, which is actually considered to belong to
cycle
n
+ 2 and therefore does not cause the output flip-flip to transition.
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...