
196
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
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 USART
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 reinitialized 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 (reset
ADEN bit in register ADCSRA) before shut down. The analog comparator cannot use
the ADC input MUX when the ADC is shut down.
12.6.3 PRR1 – Power Reduction Register 1
Bit
7
6
5
4
3
2
1
0
NA ($65)
Res
PRTRX24
PRTIM5
PRTIM4
PRTIM3
PRUSART1
PRR1
Read/Write
R
RW
Initial Value
0
Bit 7 – Res - Reserved Bit
This bit is reserved for future use. A read access always will return zero. A write access
does not modify the content.
Bit 6 – PRTRX24 - Power Reduction Transceiver
Writing a logic one to this bit shuts down the transceiver (disconnect from the power
supply). In power-down and power-save modes the power-chain will be disabled when
this bit is one. Writing a logic zero to this bit will re-enable the transceiver.
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.
Bit 0 – PRUSART1 - Power Reduction USART1
Writing a logic one to this bit shuts down the USART1 by stopping the clock to the
module. When waking up the USART1 again, the USART1 should be reinitialized to
ensure proper operation.