ATTINY25V-15ST Atmel, ATTINY25V-15ST Datasheet - Page 43

• Manufacturer Part Number: ATTINY25V-15ST
• Description: MCU AVR 2K FLASH 4MHZ 8-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25V-15ST

• Package / Case: 8-SOIC (3.9mm Width)
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Speed: 8MHz
• Number Of I /o: 6
• Eeprom Size: 128 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Program Memory Size: 2KB (2K x 8)
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Processor Series: ATTINY2x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7598H–AVR–07/09
In safety level 1, WDE is overridden by WDRF in MCUSR. See
MCUSR” on page 40
is set. To clear WDE, WDRF must be cleared before disabling the Watchdog with the procedure
described above. This feature ensures multiple resets during conditions causing failure, and a
safe start-up after the failure.
Note:
• Bits 5, 2..0 – WDP3..0: Watchdog Timer Prescaler 3, 2, 1, and 0
The WDP3..0 bits determine the Watchdog Timer prescaling when the Watchdog Timer is
enabled. The different prescaling values and their corresponding Timeout Periods are shown in
Table
Table 8-7.
Note:
WDP3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
8-7.
If the watchdog timer is not going to be used in the application, it is important to go through a
watchdog disable procedure in the initialization of the device. If the Watchdog is accidentally
enabled, for example by a runaway pointer or brown-out condition, the device will be reset, which
in turn will lead to a new watchdog reset. To avoid this situation, the application software should
always clear the WDRF flag and the WDE control bit in the initialization routine.
1. If selected, one of the valid settings below 0b1010 will be used.
WDP2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Watchdog Timer Prescale Select
WDP1
for description of WDRF. This means that WDE is always set when WDRF
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Number of WDT Oscillator
1024K cycles
128K cycles
256K cycles
512K cycles
16K cycles
32K cycles
64K cycles
2K cycles
4K cycles
8K cycles
Cycles
Reserved
ATtiny25/45/85
“MCU Status Register –
(1)
Typical Time-out at
V
CC
0.125 s
16 ms
32 ms
64 ms
0.25 s
0.5 s
1.0 s
2.0 s
4.0 s
8.0 s
= 5.0V
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