ATMEGA8A-AUR Atmel, ATMEGA8A-AUR Datasheet - Page 32

• Manufacturer Part Number: ATMEGA8A-AUR
• Description: MCU AVR 8KB FLASH 16MHZ 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8A-AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9. Power Management and Sleep Modes
9.1
8159D–AVR–02/11
Sleep Modes
Sleep modes enable the application to shut down unused modules in the MCU, thereby saving
power. The AVR provides various sleep modes allowing the user to tailor the power consump-
tion to the application’s requirements.
Figure 8-1 on page 24
tion. The figure is helpful in selecting an appropriate sleep mode.
clock options and their wake-up sources.
Table 9-1.
Notes:
To enter any of the five sleep modes, the SE bit in MCUCR must be written to logic one and a
SLEEP instruction must be executed. The SM2, SM1, and SM0 bits in the MCUCR Register
select which sleep mode (Idle, ADC Noise Reduction, Power-down, Power-save, or Standby)
will be activated by the SLEEP instruction. See
If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU wakes up. The MCU
is then halted for four cycles in addition to the start-up time, it executes the interrupt routine, and
resumes execution from the instruction following SLEEP. The contents of the Register File and
SRAM are unaltered when the device wakes up from sleep. If a reset occurs during sleep mode,
the MCU wakes up and executes from the Reset Vector.
Note that the Extended Standby mode present in many other AVR MCUs has been removed in
the ATmega8A, as the TOSC and XTAL inputs share the same physical pins.
Sleep Mode
Idle
ADC Noise
Reduction
Power-down
Power-save
Standby
1. External Crystal or resonator selected as clock source.
2. If AS
3. Only level interrupt INT1 and INT0.
(1)
Active Clock Domains and Wake-up Sources in the Different Sleep Modes
2
bit in ASSR is set.
Active Clock Domains
presents the different clock systems in the ATmega8A, and their distribu-
X
X
X
X
X
X
(2)
Table 9-1
Oscillators
X
X
X
X
X
X
(2)
(2)
(2)
for a summary.
X
X
X
X
X
(3)
(3)
(3)
(3)
Table 9-1
Wake-up Sources
X
X
X
X
X
ATmega8A
shows the different
X
X
X
(2)
X
X
X
X
X
32