Jijtlilnjijijtrlmj, Toshiba, Ttytytytxt)r – Toshiba TMP87CP24AF User Manual
Page 70
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TOSHIBA
TMP87CM24A/P24A
(4)
Window mode
Counting
up
is
performed
on
the
rising
edge
of
the
pulse
that
is
the
logical
AND-ed
product
of
the
TCI
pin
input
(window
pulse)
and
an
internal
clock.
The
contents
of
TREG1A
are
compared
with
the
contents
of
up-counter.
If
a
match
is
found,
an
INTTC1
interrupt
is
generated,
and
the
counter
is
cleared.
Positive
or
negative
logic
for
the
TCI
pin
input
can
be
selected
with
INT2ES.
Setting
SCAP1
to
"1"
transférés
the
current
contents
of
up-counter
to
TREG1B.
It
is
necessary
that
the
maximum
applied
frequency
(TCI
input)
be
such
that
the
counter
value
can
be
analyzed
by
the
program.
That
is, the frequency must be considerably slower than the selected internal clock.
Command start
I
TCI pin input
Internal clock
Up-counter
TREG1A
INTTC1 interrupt
jiJtLilnjiJiJTrlmj^^
1
______X
t
_____________________________________________________ <
Match
w
Clear
(a) Positive Logic (INT2ES = 0)
TCI pin input
Internal clock
Up-counter
TREG1A
INTTC1 interrupt
Command start
----- i------
0
)TTYTYTYTXT)r
6
X
Match
Clear
(b) Negative Logic (INT2ES = 1)
Figure 2-19. Window Mode Timing Chart
(5)
Pulse width measurement mode
Counting
is
started
by
the
external
trigger
(set
to
external
trigger
start
by
TCI
S).
The
trigger
can
be
selected
either
the
rising
or
falling
edge
of
the
TCI
pin
input.
The
source
clock
is
used
an
internal
clock.
On
the
next
falling
(rising)
edge,
the
counter
contents
are
transferred
to
TREG1B
and
an
INTTC1
interrupt
is
generated.
The
counter
is
cleared
when
the
single
edge
capture
mode
is
set.
When
double
edge
capture
is
set,
the
counter
continues
and,
at
the
next
rising
(falling)
edge,
the
counter
contents
are
again
transferred
toTREGIB.
If
a
falling
(rising)
edge
capture
value
is
required,
it
is
necessary
to
read
out
TREG1B
contents
until
a
rising
(falling)
edge
is
detected.
Falling
or
rising
edge
is
selected
with
INT2ES,
and
single
edge
or
double
edge
is
selected
with
MCAP1
(
bit
6
in
TC1CR).
3
-
24-70
2002
-
10-03