ATTINY85-20PU Atmel, ATTINY85-20PU Datasheet - Page 45
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ATTINY85-20PU
Manufacturer Part Number
ATTINY85-20PU
Description
IC AVR MCU 8K 20MHZ 8DIP
Manufacturer
Atmel
Series
AVR® ATtinyr
Datasheets
1.ATTINY25-20MU.pdf
(236 pages)
2.ATTINY25-20PU.pdf
(30 pages)
3.ATTINY85-20PU.pdf
(234 pages)
Specifications of ATTINY85-20PU
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
8KB (4K x 16)
Program Memory Type
FLASH
Eeprom Size
512 x 8
Ram Size
512 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
8-DIP (0.300", 7.62mm)
Processor Series
ATTINY8x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
512 B
Interface Type
USI
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
6
Number Of Timers
2
Operating Supply Voltage
2.7 V to 5.5 V
Maximum Operating Temperature
+ 85 C
Mounting Style
Through Hole
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
On-chip Adc
4-ch x 10-bit
Controller Family/series
AVR Tiny
No. Of I/o's
6
Eeprom Memory Size
512Byte
Ram Memory Size
512Byte
Cpu Speed
20MHz
No. Of Timers
2
Rohs Compliant
Yes
Cpu Family
ATtiny
Device Core
AVR
Device Core Size
8b
Frequency (max)
20MHz
Total Internal Ram Size
512Byte
# I/os (max)
6
Number Of Timers - General Purpose
2
Operating Supply Voltage (typ)
3.3/5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
2.7V
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Through Hole
Pin Count
8
Package Type
PDIP
For Use With
ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRBC100 - REF DESIGN KIT BATTERY CHARGER770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEM
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATTINY85-20PU
Manufacturer:
CUI
Quantity:
1 000
8.4.1
8.4.1.1
8.4.1.2
2586M–AVR–07/10
Timed Sequences for Changing the Configuration of the Watchdog Timer
Safety Level 1
Safety Level 2
“Timed Sequences for Changing the Configuration of the Watchdog Timer” on page 45
details.
Table 8-1.
Figure 8-7.
The sequence for changing configuration differs slightly between the two safety levels. Separate
procedures are described for each level.
In this mode, the Watchdog Timer is initially disabled, but can be enabled by writing the WDE bit
to one without any restriction. A timed sequence is needed when disabling an enabled Watch-
dog Timer. To disable an enabled Watchdog Timer, the following procedure must be followed:
In this mode, the Watchdog Timer is always enabled, and the WDE bit will always read as one. A
timed sequence is needed when changing the Watchdog Time-out period. To change the
Watchdog Time-out, the following procedure must be followed:
WDTON
Unprogrammed
Programmed
1. In the same operation, write a logic one to WDCE and WDE. A logic one must be writ-
2. Within the next four clock cycles, in the same operation, write the WDE and WDP bits
1. In the same operation, write a logical one to WDCE and WDE. Even though the WDE
2. Within the next four clock cycles, in the same operation, write the WDP bits as desired,
ten to WDE regardless of the previous value of the WDE bit.
as desired, but with the WDCE bit cleared.
always is set, the WDE must be written to one to start the timed sequence.
but with the WDCE bit cleared. The value written to the WDE bit is irrelevant.
WDT Configuration as a Function of the Fuse Settings of WDTON
Watchdog Timer
Safety
Level
1
2
WATCHDOG
OSCILLATOR
RESET
128 kHz
WDP0
WDP1
WDP2
WDP3
WDE
WDT Initial
State
Disabled
Enabled
How to Disable the
WDT
Timed sequence
Always enabled
MCU RESET
PRESCALER
WATCHDOG
How to Change Time-
out
No limitations
Timed sequence
for
45