Information

38.4.1 Wait mode operation
During Wait mode, the CMT if enabled, will continue to operate normally. However,
there is no change in operating modes of CMT during Wait mode, because the CPU is not
operating.
38.4.2 Stop mode operation
This section describes the CMT Stop mode operations.
38.4.2.1 Normal Stop mode operation
During Normal Stop mode, clocks to the CMT module are halted. No registers are
affected.
The CMT module will resume upon exit from Normal Stop mode because the clocks are
halted. Software must ensure that the Normal Stop mode is not entered while the
modulator is still in operation so as to prevent the IRO signal from being asserted while
in Normal Stop mode. This may require a timeout period from the time that
MSC[MCGEN] is cleared to allow the last modulator cycle to complete.
38.4.2.2 Low-Power Stop mode operation
During Low-Power Stop mode, the CMT module is completely powered off internally
and the IRO signal state is latched and held at the time when the CMT enters this mode.
To prevent the IRO signal from being asserted during Low-Power Stop mode, the
software must assure that the signal is not active when entering Low-Power Stop mode.
Upon wakeup from Low-Power Stop mode, the CMT module will be in the reset state.
38.5 CMT external signal descriptions
The following table shows the description of the external signal.
Table 38-3. CMT signal description
Signal Description I/O
CMT_IRO Infrared Output O
Chapter 38 Carrier Modulator Transmitter (CMT)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 843