Renesas F-ZTAT H8 Series, Hardware Manual

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5. Power-Down Modes
Rev.3.00 Jul. 19, 2007 page 104 of 532
REJ09B0397-0300
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 Register
Name Abbreviation R/W Initial Value Address
System control register 1 SYSCR1 R/W H'07 H'FFF0
System control register 2 SYSCR2 R/W H'E0 H'FFF1
System Control Register 1 (SYSCR1)
Bit 7 6 5 4 3 2 1 0
SSBY STS2 STS1 STS0 LSON
⎯ ⎯ ⎯
Initial value 0 0 0 0 0 1 1 1
Read/Write R/W R/W R/W R/W R/W
⎯ ⎯ ⎯
SYSCR1 is an 8-bit read/write register for control of the power-down modes.
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 (initial value)
•
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.