mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 841

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

Freescale Semiconductor, Inc.
FTM counting is up
CNTINH:L = 0x0000
MODH:L = 0x0004
FTM counter
TOF bit
period of counting = (MODH:L - CNTINH:L + 0x0001) x period of FTM counter clock
Figure 37-146. Example of FTM Up Counting with CNTIN = 0x0000
period of FTM counter clock
3
• FTM operation is only valid when the value of the
• MODH:L = CNTINH:L is a redundant condition. In this
• When MODH:L = 0x0000, CNTINH:L = 0x0000 (for
• Setting CNTINH:L to be greater than the value of
CNTINH:L registers is less than the value of the MODH:L
registers (either in the unsigned counting or signed
counting). It is the responsibility of the software to ensure
that the values in the CNTINH:L and MODH:L registers
meet this requirement. Any values of CNTINH:L and
MODH:L that do not satisfy this criteria can result in
unpredictable behavior.
case, the FTM counter is always equal to MODH:L and the
TOF bit is set in each rising edge of the FTM counter
clock.
example after reset), and FTMEN = 1, the FTM counter
remains stopped at 0x0000 until a non-zero value is written
into the MODH:L or CNTINH:L registers.
MODH:L is not recommended as this unusual setting may
make the FTM operation difficult to comprehend.
However, there is no restriction on this configuration, and
an example is shown in the following figure.
= (MODH:L + 0x0001) x period of FTM counter clock
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set TOF bit
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MCF51JF128 Reference Manual, Rev. 2, 03/2011
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Preliminary
Note
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set TOF bit
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Chapter 37 FlexTimer (FTM)
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set TOF bit
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