MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
1281
Preliminary—Subject to Change Without Notice
FRZ_ACK — Freeze Mode Acknowledge
This read-only bit indicates that FlexCAN is in Freeze Mode and its prescaler is stopped. The Freeze
Mode request cannot be granted until current transmission or reception processes have finished.
Therefore the software can poll the FRZ_ACK bit to know when FlexCAN has actually entered Freeze
Mode. If Freeze Mode request is negated, then this bit is negated once the FlexCAN prescaler is
running again. If Freeze Mode is requested while FlexCAN is in any of the low power modes, then the
FRZ_ACK bit will only be set when the low power mode is exited. See
for more information.
1 = FlexCAN in Freeze Mode, prescaler stopped
0 = FlexCAN not in Freeze Mode, prescaler running
SUPV — Supervisor Mode
This bit configures some of the FlexCAN registers to be either in Supervisor or Unrestricted memory
space. The registers affected by this bit are marked as S/U in the Access Type column of
.
Reset value of this bit is ‘1’, so the affected registers start with Supervisor access restrictions.
1 = Affected registers are in Supervisor memory space. Any access without supervisor permission
behaves as though the access was done to an unimplemented register location
0 = Affected registers are in Unrestricted memory space
SLF_WAK — Self Wake Up
This bit enables the Self Wake Up feature when FlexCAN is in Doze Mode or Stop Mode. If this bit
had been asserted by the time FlexCAN entered Doze Mode or Stop Mode, then FlexCAN will look for
a recessive to dominant transition on the bus during these modes. If a transition from recessive to
dominant is detected during Doze Mode, FlexCAN resumes its clocks and, if enabled to do so,
generates a Wake Up interrupt to the CPU. If a transition from recessive to dominant is detected during
Stop Mode, then FlexCAN generates, if enabled to do so, a Wake Up interrupt to the CPU so that it can
resume the clocks globally. This bit can not be written while the module is in Doze Mode or Stop Mode.
1 = FlexCAN Self Wake Up feature is enabled
0 = FlexCAN Self Wake Up feature is disabled
WRN_EN — Warning Interrupt Enable
When asserted, this bit enables the generation of the TWRN_INT and RWRN_INT flags in the Error
and Status Register. If WRN_EN is negated, the TWRN_INT and RWRN_INT flags will always be
zero, independent of the values of the error counters, and no warning interrupt will ever be generated.
1 = TWRN_INT and RWRN_INT bits are set when the respective error counter transition from <96
to
≥
96.
0 = TWRN_INT and RWRN_INT bits are zero, independent of the values in the error counters.
LPM_ACK — Low Power Mode Acknowledge
This read-only bit indicates that FlexCAN is either in Disable Mode, Doze Mode or Stop Mode. Either
of these low power modes can not be entered until all current transmission or reception processes have
finished, so the CPU can poll the LPM_ACK bit to know when FlexCAN has actually entered low
power mode. See
Section 28.5.9.2, “Module Disable Mode,”
Section 28.5.9.3, “Doze Mode,”
and
Section 28.5.9.4, “Stop Mode,”
for more information.