A000048 Arduino, A000048 Datasheet - Page 44

• Manufacturer Part Number: A000048
• Description: ATMEGA328 MCU IC W/ Arduino UNO Bootloader
• Manufacturer: Arduino
• Series: -r

Specifications of A000048

• Accessory Type: Pre-Programed IC
• Features: Powered Via USB Connection, AC-to-DC Adapter, Power Jack, ICSP Header
• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: -
• For Use With: ATmega328 Microcontrollers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.11
9.11.1
8271C–AVR–08/10
Register Description
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/48PA/88A/88PA/168A/168PA/328/328P, 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
Table 9-2.
Note:
• 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.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
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
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
Table
1
0
9-2.
R/W
SE
0
0
SMCR
44