ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 49

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Minimizing Power
Consumption
Analog to Digital
Converter
Analog Comparator
Brown-out Detector
Internal Voltage
Reference
Watchdog Timer
Port Pins
2490Q–AVR–06/10
There are several issues to consider when trying to minimize the power consumption in an AVR
controlled system. In general, sleep modes should be used as much as possible, and the sleep
mode should be selected so that as few as possible of the device’s functions are operating. All
functions not needed should be disabled. In particular, the following modules may need special
consideration when trying to achieve the lowest possible power consumption.
If enabled, the ADC will be enabled in all sleep modes. To save power, the ADC should be dis-
abled before entering any sleep mode. When the ADC is turned off and on again, the next
conversion will be an extended conversion. Refer to
for details on ADC operation.
When entering Idle mode, the Analog Comparator should be disabled if not used. When entering
ADC Noise Reduction mode, the Analog Comparator should be disabled. In the other sleep
modes, the Analog Comparator is automatically disabled. However, if the Analog Comparator is
set up to use the internal voltage reference as input, the Analog Comparator should be disabled
in all sleep modes. Otherwise, the internal voltage reference will be enabled, independent of
sleep mode. Refer to
log Comparator.
If the Brown-out Detector is not needed in the application, this module should be turned off. If the
Brown-out Detector is enabled by the BODEN Fuse, it will be enabled in all sleep modes, and
hence, always consume power. In the deeper sleep modes, this will contribute significantly to
the total current consumption. Refer to
configure the Brown-out Detector.
The internal voltage reference will be enabled when needed by the Brown-out Detector, the Ana-
log Comparator or the ADC. If these modules are disabled as described in the sections above,
the internal voltage reference will be disabled and it will not be consuming power. When turned
on again, the user must allow the reference to start up before the output is used. If the reference
is kept on in sleep mode, the output can be used immediately. Refer to
ence” on page 56
If the Watchdog Timer is not needed in the application, this module should be turned off. If the
Watchdog Timer is enabled, it will be enabled in all sleep modes, and hence, always consume
power. In the deeper sleep modes, this will contribute significantly to the total current consump-
tion. Refer to
When entering a sleep mode, all port pins should be configured to use minimum power. The
most important thing is then to ensure that no pins drive resistive loads. In sleep modes where
the both the I/O clock (clk
device will be disabled. This ensures that no power is consumed by the input logic when not
needed. In some cases, the input logic is needed for detecting wake-up conditions, and it will
then be enabled. Refer to the section
details on which pins are enabled. If the input buffer is enabled and the input signal is left floating
or have an analog signal level close to V
“Watchdog Timer” on page 56
for details on the start-up time.
“Analog Comparator” on page 227
I/O
) and the ADC clock (clk
“Digital Input Enable and Sleep Modes” on page 70
“Brown-out Detector” on page 49
CC
/2, the input buffer will use excessive power.
for details on how to configure the Watchdog Timer.
“Analog to Digital Converter” on page 230
ADC
for details on how to configure the Ana-
) are stopped, the input buffers of the
ATmega64(L)
“Internal Voltage Refer-
for details on how to
for
49