mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 790

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

Functional Description
36.7.3.2 Baseband Mode
Baseband mode (MSC[MCGEN] and MSC[BASE] bits are set) is a derivative of time
mode, where the mark and space period is based on (CMTCLK ÷ 8) counts. The mark
and space calculations are the same as in time mode. In this mode, the modulator output
will be at a logic 1 for the duration of the mark period and at a logic 0 for the duration of
a space period. See
modes. In the example, the carrier out frequency (f
0x01 and a low count of 0x02 that results in a divide of 3 of CMTCLK with a 33% duty
cycle. The modulator down counter was loaded with the value 0x0003 and the space
period register with 0x0002.
790
Figure 36-17. Example: CMT Output in Time and Baseband Modes with OC[CMTPOL]=0
IRO SIGNAL (TIME MODE)
M O D U L A T O R G A T E
C A R R IE R O U T (f cg )
CMTCLK
(BASEBAND MODE)
IRO SIGNAL
8
The waveforms in
purpose of conceptual illustration and are not meant to
represent precise timing relationships between the signals
shown.
Figure 36-17
MCF51JF128 Reference Manual, Rev. 2, 03/2011
MARK
Figure 36-17
for an example of the output for both baseband and time
Preliminary
Note
and
SPACE
Figure 36-18
cg
) is generated with a high count of
are for the
MARK
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