ATTINY28L-4AI Atmel, ATTINY28L-4AI Datasheet - Page 38

• Manufacturer Part Number: ATTINY28L-4AI
• Description: IC AVR MCU 2KFLSH 4MHZ 3V 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY28L-4AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 11
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Ram Size: -
• Data Converters: -
• Connectivity: -

38
ATtiny28L/V
1. In the same operation, write a logical “1” to WDTOE and WDE. A logical “1” must
2. Within the next four clock cycles, write a logical “0” to WDE. This disables the
• Bits 2..0 – WDP2, WDP1, WDP0: Watchdog Timer Prescaler 2, 1 and 0
The WDP2, WDP1 and WDP0 bits determine the Watchdog Timer prescaling when the
Watchdog Timer is enabled. The different prescaling values and their corresponding
time-out periods are shown in Table 15.
Table 15. Watchdog Timer Prescale Select
Note:
WDP2
0
0
0
0
1
1
1
1
be written to WDE even though it is set to one before the disable operation starts.
Watchdog.
The frequency of the Watchdog oscillator is voltage-dependent, as shown in the section
“Typical Characteristics” on page 57.
The WDR (Watchdog Reset) instruction should always be executed before the Watchdog
Timer is enabled. This ensures that the reset period will be in accordance with the
Watchdog Timer prescale settings. If the Watchdog Timer is enabled without reset, the
Watchdog Timer may not start counting from zero.
WDP1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
Number of WDT
Oscillator
Cycles
16K cycles
32K cycles
64K cycles
128K cycles
256K cycles
512K cycles
1,024K cycles
2,048K cycles
Typical
Time-out at
V
0.15 s
0.30 s
0.60 s
1.2 s
2.4 s
4.8 s
9.6 s
19 s
CC
= 2.0V
Typical
Time-out at
V
47 ms
94 ms
0.19 s
0.38 s
0.75 s
1.5 s
3.0 s
6.0 s
CC
= 3.0V
1062F–AVR–07/06
Typical
Time-out at
V
15 ms
30 ms
60 ms
0.12 s
0.24 s
0.49 s
0.97 s
1.9 s
CC
= 5.0V