871
(2) Exiting Software Standby Mode by
RES
or
MRES
Pins
When the
RES
pin or
MRES
pin is driven low, clock oscillation is started. At the same time as
clock oscillation starts, clocks are supplied to the entire chip. Note that the
RES
pin or
MRES
pin must be held low until clock oscillation stabilizes. When the
RES
pin or
MRES
pin goes
high, the CPU begins reset exception handling.
(3) Exiting Software Standby Mode by
STBY
Pin
When the
STBY
pin is driven low, a transition is made to hardware standby mode.
24.6.3
Setting Oscillation Stabilization Time after Clearing Software Standby Mode
Bits STS2 to STS0 in SBYCR should be set as described below.
Using a Crystal Oscillator: Set bits STS2 to STS0 so that the standby time is at least 8 ms (the
oscillation stabilization time).
Table 24-5 shows the standby times for different operating frequencies and settings of bits STS2
to STS0.
Table 24-5 Oscillation Stabilization Time Settings
STS2 STS1 STS0
Standby
Time
25
MHz
20
MHz
16
MHz
12
MHz
10
MHz
8
MHz
6
MHz
4
MHz
2
MHz Unit
0
0
0
8192
states
0.32
0.41
0.51
0.65
0.8
1.0
1.3
2.0
4.1
ms
1
16384
states
0.65
0.82
1.0
1.3
1.6
2.0
2.7
4.1
8.2
1
0
32768
states
1.3
1.6
2.0
2.7
3.3
4.1
5.5
8.2
16.4
1
65536
states
2.6
3.3
4.1
5.5
6.6
8.2
10.9 16.4
32.8
1
0
0
131072
states
5.2
6.6
8.2
10.9
13.1 16.4
21.8
32.8
65.5
1
262144
states
10.4
13.1 16.4
21.8
26.2
32.8
43.6
65.6
131.2
1
0
Reserved —
—
—
—
—
—
—
—
—
µs
1
16 states
*
0.6
0.8
1.0
1.3
1.6
2.0
1.7
4.0
8.0
: Recommended time setting
Note: * Do not use this setting in the version with built-in flash memory.