HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 607

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

18.6.3
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 18.4 shows the standby times for different operating frequencies and settings of bits STS2 to
STS0.
Table 18.4 Oscillation Stabilization Time Settings
Using an External Clock
Any value can be set. Normally, use of the minimum time is recommended.
18.6.4
Figure 18.2 shows an example in which a transition is made to software standby mode at the
falling edge on the NMI pin, and software standby mode is cleared at the rising edge on the NMI
pin.
In this example, an NMI interrupt is accepted with the NMIEG bit in SYSCR cleared to 0 (falling
edge specification), then the NMIEG bit is set to 1 (rising edge specification), the SSBY bit is set
to 1, and a SLEEP instruction is executed, causing a transition to software standby mode.
STS2 STS1 STS0 Standby Time
0
1
: Recommended time setting
0
1
0
1
Setting Oscillation Stabilization Time after Clearing Software Standby Mode
Software Standby Mode Application Example
0
1
0
1
0
1
0
1
8192 states
16384 states
32768 states
65536 states
131072 states
262144 states
Reserved
16 states
20
MHz
0.41 0.51 0.68 0.82 1.0
0.82 1.0
1.6
3.3
6.6
13.1 16.4 21.8 26.2 32.8 43.7 65.5 131.1
—
0.8
16
MHz
2.0
4.1
—
1.0
8.2
12
MHz
1.4
2.7
5.5
—
1.3
10.9 13.1 16.4 21.8 32.8 65.5
Rev.3.00 Mar. 26, 2007 Page 565 of 772
1.6
3.3
1.6
10
MHz
6.6
—
Section 18 Power-Down Modes
8
MHz
2.0
4.1
—
2.0
8.2
6
MHz
1.4
2.7
5.5
—
2.7
10.9 16.4 32.8
REJ09B0355-0300
4
MHz
2.0
4.1
—
4.0
8.2 16.4
2
MHz
4.1
—
8.0
8.2
Unit
ms
—
µs