ATTINY25-20SUR Atmel, ATTINY25-20SUR Datasheet - Page 39

• Manufacturer Part Number: ATTINY25-20SUR
• Description: MCU AVR 2KB FLASH 20MHZ 8SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25-20SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 6
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.5.2
2586M–AVR–07/10
PRR – Power Reduction Register
both BODS and BODSE must be set to one. Second, within four clock cycles, BODS must be
set to one and BODSE must be set to zero. The BODS bit is active three clock cycles after it is
set. A sleep instruction must be executed while BODS is active in order to turn off the BOD for
the actual sleep mode. The BODS bit is automatically cleared after three clock cycles.
In devices where Sleeping BOD has not been implemented this bit is unused and will always
read zero.
• Bit 5 – 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.
• Bits 4:3 – SM[1:0]: Sleep Mode Select Bits 1 and 0
These bits select between the three available sleep modes as shown in
Table 7-2.
• Bit 2 – BODSE: BOD Sleep Enable
BOD disable functionality is available in some devices, only. See
The BODSE bit enables setting of BODS control bit, as explained on BODS bit description. BOD
disable is controlled by a timed sequence.
This bit is unused in devices where software BOD disable has not been implemented and will
read as zero in those devices.
The Power Reduction Register provides a method to reduce power consumption by allowing
peripheral clock signals to be disabled.
• Bits 7:4 – Res: Reserved Bits
These bits are reserved bits in the ATtiny25/45/85 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
0x20
Read/Write
Initial Value
SM1
0
0
1
1
Sleep Mode Select
R
7
–
0
SM0
R
6
–
0
0
1
0
1
R
5
–
0
Sleep Mode
Idle
ADC Noise Reduction
Power-down
Reserved
R
4
–
0
PRTIM1
R/W
3
0
PRTIM0
R/W
2
0
“Limitations” on page
PRUSI
R/W
Table
1
0
7-2.
PRADC
R/W
0
0
37.
PRR
39