ATmega640/1280/1281/2560/2561
• Bit 5 - PRTIM0: Power Reduction Timer/Counter0
Writing a logic one to this bit shuts down the Timer/Counter0 module. When the Timer/Counter0
is enabled, operation will continue like before the shutdown.
• Bit 4 - Res: Reserved bit
This bit is reserved bit and will always read as zero.
• Bit 3 - PRTIM1: Power Reduction Timer/Counter1
Writing a logic one to this bit shuts down the Timer/Counter1 module. When the Timer/Counter1
is enabled, operation will continue like before the shutdown.
• Bit 2 - PRSPI: Power Reduction Serial Peripheral Interface
Writing a logic one to this bit shuts down the Serial Peripheral Interface by stopping the clock to
the module. When waking up the SPI again, the SPI should be re initialized to ensure proper
operation.
• Bit 1 - PRUSART0: Power Reduction USART0
Writing a logic one to this bit shuts down the USART0 by stopping the clock to the module.
When waking up the USART0 again, the USART0 should be re initialized to ensure proper
operation.
• Bit 0 - PRADC: Power Reduction ADC
Writing a logic one to this bit shuts down the ADC. The ADC must be disabled before shut down.
The analog comparator cannot use the ADC input MUX when the ADC is shut down.
11.9.3
PRR1 – Power Reduction Register 1
Bit
(0x65)
7
6
5
PRTIM5
R/W
0
4
PRTIM4
R/W
0
3
PRTIM3
R/W
0
2
PRUSART3
R/W
1
PRUSART2
R/W
0
PRUSART1
R/W
–
–
PRR1
Read/Write
R
0
R
0
Initial Value
0
0
0
• Bit 7:6 - Res: Reserved bits
These bits are reserved and will always read as zero.
• Bit 5 - PRTIM5: Power Reduction Timer/Counter5
Writing a logic one to this bit shuts down the Timer/Counter5 module. When the Timer/Counter5
is enabled, operation will continue like before the shutdown.
• Bit 4 - PRTIM4: Power Reduction Timer/Counter4
Writing a logic one to this bit shuts down the Timer/Counter4 module. When the Timer/Counter4
is enabled, operation will continue like before the shutdown.
• Bit 3 - PRTIM3: Power Reduction Timer/Counter3
Writing a logic one to this bit shuts down the Timer/Counter3 module. When the Timer/Counter3
is enabled, operation will continue like before the shutdown.
57
2549L–AVR–08/07