4 operating mode control, Toshiba – Toshiba TMP87CP24AF User Manual
Page 22
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TOSHIBA
TMP87CM24A/P24A
1.8.4 Operating Mode Control
(1)
STOP
mode (STORI, STOP2)
STOP mode is controlled by the system control register 1 (SYSCR1) and the STOP pin input. The STOP
pin is also used both as a port P20 and an INT5 (external interrupt input 5) pin. STOP mode is started
by setting STOP (bit 7 in SYSCR1) to "1". During STOP mode, the following status is maintained.
© Oscillations are turned off, and all internal operations are halted.
@
The
data
memory,
registers
(except
for
DBR)
and
port
output
latches
are
all
held
in
the
status
in
effect
before
STOP
mode
was
entered.
The
port
output
can
be
select
either
output
hold or high-impedance by setting OUTEN ( bit 4 in SYSCR1).
(3)
The divider of the timing generator is cleared to "0".
@
The
program
counter
holds
the
address
of
the
instruction
following
the
instruction
which
started the STOP mode.
STOP
mode
includes
a
level-sensitive
release
mode
and
an
edge-sensitive
release
mode,
either
of
which can be selected with RELM (bit
6
in SYSCR1).
a. Level-sensitive release mode (RELM = 1)
In
this
mode,
STOP
mode
is
released
by
setting
the
STOP
pin
high.
This
mode
is
used
for
capacitor back-up when the main power supply is cut off and long term battery back-up.
When
the
STOP
pin
input
is
high,
executing
an
instruction
which
starts
the
STOP
mode
will
not
place
in
STOP
mode
but
instead
will
immediately
start
the
release
sequence
(warm-up).
Thus,
to
start
STOP
mode
in
the
level-sensitive
release
mode,
it
is
necessary
for
the
program
to
first
confirm that the STOP pin input is low. The following method can be used for confirmation:
• Using an external interrupt input INT5 (INT5 is a falling edge-sensitive input).
Example : Starting STOP mode with an INT5 interrupt.
PINTS :
SINT5 :
TEST
(P2). 0
; To reject noise, the STOP mode does not start if
JRS
F, SINTS
port P20 is at high
LD
(SYSCR1),01000000B
; Sets up the level-sensitive release mode.
SET
(SYSCRD.7
; Starts STOP mode
LDW
(IL), 1110011101010111B
; IL12, 11,7, S,3<-0
RETI
STOP pin
XOUTpin
fi
HI
NORMAL
operation
T
______ STOP ____________
operation
Confirm by program that the
STOP pin input is low and
start STOP mode.
V
Warm-up
NORMAL
operation
STOP mode is released by the hardware.
/ Always released if the STOP \
V
pin input is high.__________
J
Figure 1-16. Level-sensitive Release Mode
Note 1:
Note 2:
After warm-up start, even /f STOP pin input is low again, STOP mode does not restart.
When changing to the level-sensitive release mode from the edge-sensitive release
mode, the release mode is not switched until a rising edge of the STOP pin input is
detected.
3
-
24-22
2002
-
10-03