Hitachi H8/3937 Series Hardware Manual page 480

SYSCR1—System control register 1
Bit 7
SSBY
Initial value 0
Read/Write R/W
Software standby
0 • When a SLEEP instruction is executed in active mode, a transition is
1
468
6 5
STS2 STS1
0 0
R/W R/W
Standby timer select 2 to 0
0 0 0
1 0
1 0 0
1 0
made to sleep mode
• When a SLEEP instruction is executed in subactive mode, a transition
is made to subsleep mode
• When a SLEEP instruction is executed in active mode, a transition is
made to standby mode or watch mode
• When a SLEEP instruction is executed in subactive mode, a transition
is made to watch mode
4 3
STS0 LSON
0 0
R/W R/W
Low speed on flag
0 The CPU operates on the system clock (ø)
1 The CPU operates on the subclock (ø
Wait time = 8,192 states
1 Wait time = 16,384 states
Wait time = 1,024 states
1 Wait time = 2,048 states
Wait time = 4,096 states
1
Wait time = 2 states
Wait time = 8 states
1
Wait time = 16 states
H'F0 System control
2 1
— MA1 MA0
1 1
— R/W R/W
Active (medium-speed)
mode clock select
0 0 ø /16
osc
1 ø /32
osc
ø /64
1 0
osc
ø /128
1
osc
0
1
)
SUB