AT90S2313-4PI Atmel, AT90S2313-4PI Datasheet - Page 38

• Manufacturer Part Number: AT90S2313-4PI
• Description: IC MCU 2K 4MHZ UART LV IT 20DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S2313-4PI

• 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: 15
• 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 ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

38
AT90S2313
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 1 before the disable operation starts.
Watchdog.
1. The frequency of the Watchdog Oscillator is voltage-dependent, as shown in the
WDP1
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 counting from zero.
To avoid unintentional MCU Reset, the Watchdog Timer should be disabled or reset
before changing the Watchdog Timer Prescale Select.
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
(1)
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
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
0839I–AVR–06/02