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S912XEG128J2MAA Datasheet, PDF (555/1324 Pages) Freescale Semiconductor, Inc – Microcontrollers | |||
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Chapter 14 Enhanced Capture Timer (ECT16B8CV3)
NOTE
When TFFCA = 1, the ï¬ag cannot be cleared via the normal ï¬ag clearing
mechanism (writing a one to the ï¬ag). Reference Section 14.3.2.6, âTimer
System Control Register 1 (TSCR1)â.
All bits reset to zero.
Table 14-25. MCFLG Field Descriptions
Field
Description
7
MCZF
Modulus Counter Underï¬ow Flag â The ï¬ag is set when the modulus down-counter reaches 0x0000.
The ï¬ag indicates when interrupt conditions have occurred. The ï¬ag can be cleared via the normal ï¬ag clearing
mechanism (writing a one to the ï¬ag) or via the fast ï¬ag clearing mechanism (Reference TFFCA bit in
Section 14.3.2.6, âTimer System Control Register 1 (TSCR1)â).
3:0
POLF[3:0]
First Input Capture Polarity Status â These are read only bits. Writes to these bits have no effect.
Each status bit gives the polarity of the ï¬rst edge which has caused an input capture to occur after capture latch
has been read.
Each POLFx corresponds to a timer PORTx input.
0 The ï¬rst input capture has been caused by a falling edge.
1 The ï¬rst input capture has been caused by a rising edge.
14.3.2.21 ICPAR â Input Control Pulse Accumulators Register (ICPAR)
Module Base + 0x0028
7
6
5
4
R
0
0
0
0
W
Reset
0
0
0
0
= Unimplemented or Reserved
3
PA3EN
0
2
PA2EN
0
1
PA1EN
0
0
PA0EN
0
Figure 14-44. Input Control Pulse Accumulators Register (ICPAR)
Read: Anytime
Write: Anytime.
All bits reset to zero.
The 8-bit pulse accumulators PAC3 and PAC2 can be enabled only if PAEN in PACTL is cleared. If PAEN
is set, PA3EN and PA2EN have no effect.
The 8-bit pulse accumulators PAC1 and PAC0 can be enabled only if PBEN in PBCTL is cleared. If PBEN
is set, PA1EN and PA0EN have no effect.
Table 14-26. ICPAR Field Descriptions
Field
3:0
8-Bit Pulse Accumulator âxâ Enable
PA[3:0]EN 0 8-Bit Pulse Accumulator is disabled.
1 8-Bit Pulse Accumulator is enabled.
Description
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor
555
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