Chapter 14 Enhanced Capture Timer (ECT16B8CV3)
MC9S12XE-Family Reference Manual , Rev. 1.19
550
Freescale Semiconductor
14.3.2.20 16-Bit Modulus Down-Counter FLAG Register (MCFLG)
Read: Anytime
Write only used in the flag clearing mechanism for bit 7. Writing a one to bit 7 clears the flag. Writing a
zero will not affect the current status of the bit.
NOTE
When TFFCA = 1, the flag cannot be cleared via the normal flag clearing
mechanism (writing a one to the flag). Reference
System Control Register 1 (TSCR1)”
.
All bits reset to zero.
14.3.2.21 ICPAR — Input Control Pulse Accumulators Register (ICPAR)
Read: Anytime
Module Base + 0x0027
7
6
5
4
3
2
1
0
R
MCZF
0
0
0
POLF3
POLF2
POLF1
POLF0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 14-42. 16-Bit Modulus Down-Counter FLAG Register (MCFLG)
Table 14-24. MCFLG Field Descriptions
Field
Description
7
MCZF
Modulus Counter Underflow Flag
— The flag is set when the modulus down-counter reaches 0x0000.
The flag indicates when interrupt conditions have occurred. The flag can be cleared via the normal flag clearing
mechanism (writing a one to the flag) or via the fast flag clearing mechanism (Reference TFFCA bit in
Section 14.3.2.6, “Timer System Control Register 1 (TSCR1)”
).
3:0
POLF[3:0]
First Input Capture Polarity Status
— These are read only bits. Writes to these bits have no effect.
Each status bit gives the polarity of the first 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 first input capture has been caused by a falling edge.
1 The first input capture has been caused by a rising edge.
Module Base + 0x0028
7
6
5
4
3
2
1
0
R
0
0
0
0
PA3EN
PA2EN
PA1EN
PA0EN
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 14-43. Input Control Pulse Accumulators Register (ICPAR)
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages