ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 44

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

10.11 Register Description
10.11.1
44
Atmel ATmega48PA/88PA/168PA [Preliminary]
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 Atmel
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
Table 10-2.
• 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 pro-
grammer’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.
Note:
Bit
0x33 (0x53)
Read/Write
Initial Value
SM2
0
0
0
0
1
1
1
1
1. Standby mode is only recommended for use with external crystals or resonators.
Sleep Mode Select
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
ATmega48PA/88PA/168PA, and will always be read as
R
4
–
0
Sleep Mode
Idle
ADC Noise Reduction
Power-down
Power-save
Reserved
Reserved
Standby
External Standby
SM2
R/W
3
0
(1)
SM1
R/W
2
0
(1)
SM0
R/W
1
0
Table
10-2.
R/W
SE
0
0
9223B–AVR–09/11
SMCR