Information

IR O SIGNAL
MODULATOR GATE
CARRIER OUT (f
cg
)
MARK1
SPACE1
MARK2
SPACE2
MARK1
MARK2
SPACE1
Figure 40-18. Example: CMT Output in FSK Mode
40.7.4 Extended Space Operation
In either time, baseband or FSK mode, the space period can be made longer than the
maximum possible value of the space period register . Setting MSC[EXSPC] bit will
force the modulator to treat the next modulation period (beginning with the next load of
the counter and space period register) as a space period equal in length to the mark and
space counts combined . Subsequent modulation periods will consist entirely of these
extended space periods with no mark periods . Clearing MSC[EXSPC] will return the
modulator to standard operation at the beginning of the next modulation period .
40.7.4.1 EXSPC Operation in Time Mode
To calculate the length of an extended space in time or baseband mode, add the mark and
space times and multiply by the number of modulation periods when MSC[EXSPC] is
set.
t
exspace
= (t
mark
+ t
space
) x (number of modulation periods)
For an example of extended space operation, see the following figure.
Note
The extended space enable feature can be used to emulate a
zero mark event.
Functional Description
K10 Sub-Family Reference Manual, Rev. 6, Nov 2011
1056 Freescale Semiconductor, Inc.