3069RF-ZTAT Datasheet, PDF (82/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

3.3 System Control Register (SYSCR)
SYSCR is an 8-bit register that controls the operation of the H8/3069R.
Bit
Initial value
Read/Write
7
SSBY
0
R/W
6
STS2
0
R/W
5
STS1
0
R/W
4
STS0
0
R/W
3
2
1
0
UE NMIEG SSOE RAME
1
0
0
1
R/W
R/W
R/W
R/W
RAM enable
Enables or
disables
on-chip RAM
Software standby output
port enable
Selects the output state
of the address bus
and bus control signals
in software standby mode
NMI edge select
Selects the valid edge
of the NMI input
User bit enable
Selects whether to use the UI bit in CCR
as a user bit or an interrupt mask bit
Standby timer select 2 to 0
These bits select the waiting time at
recovery from software standby mode
Software standby
Enables transition to software standby mode
Bit 7—Software Standby (SSBY): Enables transition to software standby mode. (For further
information about software standby mode see section 20, Power-Down State.)
When software standby mode is exited by an external interrupt, this bit remains set to 1. To clear
this bit, write 0.
Bit 7
SSBY
0
1
Description
SLEEP instruction causes transition to sleep mode
SLEEP instruction causes transition to software standby mode
(Initial value)
Rev. 5.0, 09/04, page 60 of 978