Register Configuration; System Control Register (Syscr) - Renesas F-ZTAT H8 Series Hardware Manual

21.2

Register Configuration

The H8/3048 Group has a system control register (SYSCR) that controls the power-down state,
and a module standby control register (MSTCR) that controls the module standby function. Table
21.2 summarizes these registers.
Table 21.2 Control Register
Address* Name
H'FFF2 System control register
H'FF5E Module standby control register
Note: * Lower 16 bits of the address.
21.2.1

System Control Register (SYSCR)

Bit 7
SSBY
Initial value 0
Read/Write R/W
Software standby
Enables transition to
software standby mode
SYSCR is an 8-bit readable/writable register. Bit 7 (SSBY) and bits 6 to 4 (STS2 to STS0) control
the power-down state. For information on the other SYSCR bits, see section 3.3, System Control
Register (SYSCR).
6 5
STS2 STS1 STS0
0 0
R/W R/W R/W
Standby timer select 2 to 0
These bits select the
waiting time at exit from
software standby mode
Section 21 Power-Down State
Abbreviation R/W
SYSCR R/W
MSTCR R/W
4 3 2
UE NMIEG
0 1 0
R/W R/W
NMI edge select
User bit enable
Rev. 7.00 Sep 21, 2005 page 665 of 878
Initial Value
H'0B
H'40
1 0
— RAME
1 1
— R/W
RAM enable
Reserved bit
REJ09B0259-0700