AT90S8515-4PI Atmel, AT90S8515-4PI Datasheet - Page 43

• Manufacturer Part Number: AT90S8515-4PI
• Description: IC MCU 8K FLSH 4MHZ LV IT 40DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S8515-4PI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• 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 ~ 6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

0841G–09/01
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 14.
Table 14. 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 Electrical
Characteristics section.
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 to count from zero.
To avoid unintentional MCU reset, the Watchdog Timer should be disabled or reset
before changing the Watchdog Timer Prescale Select.
WDP1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
Number of WDT
Oscillator Cycles
1,024K cycles
2,048K cycles
128K cycles
256K cycles
512K cycles
16K cycles
32K cycles
64K cycles
Typical Time-out
at V
CC
47.0 ms
94.0 ms
0.19 s
0.38 s
0.75 s
= 3.0V
1.5 s
3.0 s
6.0 s
AT90S8515
Typical Time-out
at V
CC
15.0 ms
30.0 ms
60.0 ms
0.12 s
0.24 s
0.49 s
0.97 s
= 5.0V
1.9 s
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