59
Bits 6 to 4—Standby Timer Select (STS2 to STS0): These bits select the length of time the CPU
and on-chip supporting modules wait for the internal clock oscillator to settle when software
standby mode is exited by an external interrupt. Set these bits so that the waiting time will be at
least 7 ms at the system clock rate. For further information about waiting time selection, see
section 17.4.3, Selection of Oscillator Waiting Time after Exit from Software Standby Mode.
Bit6
STS2
Bit5
STS1
Bit4
STS0
Description
0
0
0
Waiting time = 8,192 states
(Initial value)
0
0
1
Waiting time = 16,384 states
0
1
0
Waiting time = 32,768 states
0
1
1
Waiting time = 65,536 states
1
0
0
Waiting time = 131,072 states
1
0
1
Waiting time = 1,024 states
1
1
—
Illegal setting
Bit 3—User Bit Enable (UE): Selects whether to use the UI bit in the condition code register as a
user bit or an interrupt mask bit.
Bit 3
UE
Description
0
UI bit in CCR is used as an interrupt mask bit
1
UI bit in CCR is used as a user bit
(Initial value)
Bit 2—NMI Edge Select (NMIEG): Selects the valid edge of the NMI input.
Bit2
NMIEG
Description
0
An interrupt is requested at the falling edge of NMI
(Initial value)
1
An interrupt is requested at the rising edge of NMI
Bit 1—Reserved: This bit cannot be modified and is always read as 1.
Bit 0—RAM Enable (RAME): Enables or disables the on-chip RAM. The RAME bit is
initialized by the rising edge of the
RES
signal. It is not initialized in software standby mode.
Bit 0
RAME
Description
0
On-chip RAM is disabled
1
On-chip RAM is enabled
(Initial value)