Atmel ATmega328P Xplained Mini MEGA328P-XMINI MEGA328P-XMINI Data Sheet
Product codes
MEGA328P-XMINI
45
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
10.11 Register Description
10.11.1 SMCR – Sleep Mode Control Register
The Sleep Mode Control Register contains control bits for power management.
• Bits [7:4]: Reserved
These bits are unused in the ATmega48A/PA/88A/PA/168A/PA/328/P, and will always be read as zero.
• Bits 3:1 – SM[2:0]: Sleep Mode Select Bits 2, 1, and 0
These bits select between the five available sleep modes as shown in
.
Note:
1.
Standby mode is only recommended for use with external crystals or resonators.
• Bit 0 – SE: Sleep Enable
The SE bit must be written to logic one to make the MCU enter the sleep mode when the SLEEP instruction is
executed. To avoid the MCU entering the sleep mode unless it is the programmer’s purpose, it is recommended
to write the Sleep Enable (SE) bit to one just before the execution of the SLEEP instruction and to clear it
immediately after waking up.
executed. To avoid the MCU entering the sleep mode unless it is the programmer’s purpose, it is recommended
to write the Sleep Enable (SE) bit to one just before the execution of the SLEEP instruction and to clear it
immediately after waking up.
Bit
7
6
5
4
3
2
1
0
–
–
–
–
SM2
SM1
SM0
SE
SMCR
Read/Write
R
R
R
R
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Table 10-2.
Sleep Mode Select
SM2
SM1
SM0
Sleep Mode
0
0
0
Idle
0
0
1
ADC Noise Reduction
0
1
0
Power-down
0
1
1
Power-save
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Standby
1
1
1
External Standby