Toshiba – Toshiba TMP87CP24AF User Manual
Page 19
Attention! The text in this document has been recognized automatically. To view the original document, you can use the "Original mode".
TOSHIBA
TMP87CM24A/P24A
(2) Dual-dock mode
Both
high-frequency
and
low-frequency
oscillation
circuits
are
used
in
this
mode.
Pins
P21
(XTIN)
and
P22
(XTOUT)
cannot
be
used
as
input/output
ports.
The
main
system
clock
is
obtained
from
the
high-frequency
clock
in
NORMAL2
and
IDLE2
modes,
and
is
obtained
from
the
low-frequency
clock
in SLOW and SLEEP modes. The machine cycle time is 4/fc [s] (0.5 fjs at fc =
8
MHz) in NORMAL2 and
IDLE2 modes, and 4/fs [s] (122 fxs at fs = 32.768 kHz) in SLOW and SLEEP modes. Note that the
TMP87PP24
is
placed
in
the
single-clock
mode
during
reset. To use the dual-clock mode, the low-
frequency oscillator should be turned on by executing [SET (SYSCR2).XTEN] instruction.
© NORMAL2mode
In
this
mode,
the
CPU
core
operates
using
the
high-frequency
clock.
On-chip
peripherals
operate
using
the
high-frequency
clock
and/or
low-frequency
clock.
In
case
that
the
dual
clock
mode
has
been
selected
by
an
option,
the
TMP87CM24A/P24A
are
placed
in
this
mode
after reset.
@ SLOW mode
This
mode
can
be
used
to
reduce
power-consumption
by
turning
off
oscillation
of
the
high-
frequency
clock.
The
CPU
core
and
on-chip
peripherals
operate
using
the
low-frequency
clock.
Switching
back
and
forth
between
NORMAL2
and
SLOW
modes
is
performed
by
the
system
control register
2
.
(3)
IDLE2mode
In
this
mode,
the
internal
oscillation
circuits
remain
active.
The
CPU
and
the
watchdog
timer
are
halted;
however,
on-chip
peripherals
remain
active
(operate
using
the
high-frequency
clock
and/or
the
low-frequency
clock).
Starting
and
releasing
of
IDLE2
mode
are
the
same
as
for IDLE1 mode, except that operation returns to NORMAL2 mode.
® SLEEP mode
In
this
mode,
the
internal
oscillation
circuit
of
the
low-frequency
clock
remains
active.
The
CPU,
the
watchdog
timer,
and
the
internal
oscillation
circuit
of
the
high-frequency
clock
are
halted;
however,
on-chip
peripherals
remain
active
(operate
using
the
low-frequency
clock).
Starting
and
releasing
of
SLEEP
mode
is
the
same
as
for
IDLE1
mode,
except
that
operation
returns to SLOW mode.
(D STOP2 mode
As in STOP1 mode, all system operations are halted in this mode.
3
-
24-19
2002
-
10-03