ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 54

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Register Description
SMCR – Sleep Mode Control
Register
54
ATmega640/1280/1281/2560/2561
The Sleep Mode Control Register contains control bits for power management.
• Bits 3, 2, 1 – SM2:0: Sleep Mode Select Bits 2, 1, and 0
These bits select between the five available sleep modes as shown in Table 25.
Table 25. Sleep Mode Select
Note:
• Bit 1 – 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 wak-
ing up.
Bit
0x33 (0x53)
Read/Write
Initial Value
SM2
0
0
0
0
1
1
1
1
1. Standby modes are only recommended for use with external crystals or resonators.
R
7
–
0
SM1
0
0
1
1
0
0
1
1
R
6
–
0
R
5
–
0
SM0
0
1
0
1
0
1
0
1
R
4
–
0
Sleep Mode
Idle
ADC Noise Reduction
Power-down
Power-save
Reserved
Reserved
Standby
Extended Standby
SM2
R/W
3
0
(1)
SM1
R/W
2
0
(1)
SM0
R/W
1
0
R/W
SE
0
0
2549K–AVR–01/07
SMCR