Section 5 Power-Down Modes
5.1.1
System Control Registers
The operation mode is selected using the system control registers described in table 5.3.
Table 5.3
System Control Registers
Name
System control register 1
System control register 2
1. System Control Register 1 (SYSCR1)
Bit
7
SSBY
Initial value
0
Read/Write
R/W
SYSCR1 is an 8-bit read/write register for control of the power-down modes.
Upon reset, SYSCR1 is initialized to H'07.
Bit 7: Software standby (SSBY)
This bit designates transition to standby mode or watch mode.
Bit 7
SSBY
Description
0
•
When a SLEEP instruction is executed in active mode,
a transition is made to sleep mode
•
When a SLEEP instruction is executed in subactive mode, a transition is made
to subsleep mode
1
•
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
Rev. 6.00 Aug 04, 2006 page 134 of 680
REJ09B0145-0600
Abbreviation
SYSCR1
SYSCR2
6
5
STS2
STS1
STS0
0
0
R/W
R/W
R/W
R/W
Initial Value
R/W
H'07
R/W
H'F0
4
3
2
LSON
0
0
1
R/W
Address
H'FFF0
H'FFF1
1
0
MA1
MA0
1
1
R/W
R/W
(initial value)