Datasheet

ATmega640/1280/1281/2560/2561

2549K–AVR–01/07

PRR0 – Power Reduction

• Bit 7 - PRTWI: Power Reduction TWI

Writing a logic one to this bit shuts down the TWI by stopping the clock to the module.

When waking up the TWI again, the TWI should be re initialized to ensure proper

operation.

• Bit 6 - PRTIM2: Power Reduction Timer/Counter2

Writing a logic one to this bit shuts down the Timer/Counter2 module in synchronous

mode (AS2 is 0). When the Timer/Counter2 is enabled, operation will continue like

before the shutdown.

• 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 mod-

ule. 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.

Bit 7 6 543 2 1 0

(0x64) PRTWI PRTIM2 PRTIM0 – PRTIM1 PRSPI PRUSART0 PRADC PRR0

Read/Write R/W R/W R/W RR/W R/W R/W R/W

Initial Value 0 0 0 0 0 0 0 0