2 prr – power reduction register – Rainbow Electronics ATtiny10 User Manual

Page 26

8127B–AVR–08/09

ATtiny4/5/9/10

• Bits 3:1 – SM2..SM0: Sleep Mode Select Bits 2..0

These bits select between available sleep modes, as shown in

Table 7-2

Note:

1. This mode is available in all devices, although only ATtiny5/10 are equipped with an ADC

• Bit 0 – SE: Sleep Enable

The SE bit must be written to logic one to make the MCU enter the sleep mode when the SLEEP
instruction is executed. To avoid the MCU entering the sleep mode unless it is the programmer’s
purpose, it is recommended to write the Sleep Enable (SE) bit to one just before the execution of
the SLEEP instruction and to clear it immediately after waking up.

7.4.2

PRR – Power Reduction Register

• Bits 7:2 – Res: Reserved Bits

These bits are reserved and will always read zero.

• Bit 1 – 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.

The ADC is available in ATtiny5/10, only.

• Bit 0 – 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.

Table 7-2.

Sleep Mode Select

SM2

SM1

SM0

Sleep Mode

Idle

ADC noise reduction

(1)

Power-down

Reserved

Standby

Reserved

Bit

7 6 5 4 3 2 1 0

0x35

–

– PRADC

PRTIM0

PRR

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

R/W

Initial

Value

0 0 0 0 0 0 0 0