ATMEGA169-16AU Atmel, ATMEGA169-16AU Datasheet - Page 44

• Manufacturer Part Number: ATMEGA169-16AU
• Description: IC AVR MCU 16K 16MHZ 5V 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA169-16AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: ATAVRBFLY - KIT EVALUATION AVR BUTTERFLYATSTK502 - MOD EXPANSION AVR STARTER 500
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

44
ATmega169/V
• Bit 3 – WDE: Watchdog Enable
When the WDE is written to logic one, the Watchdog Timer is enabled, and if the WDE is
written to logic zero, the Watchdog Timer function is disabled. WDE can only be cleared
if the WDCE bit has logic level one. To disable an enabled Watchdog Timer, the follow-
ing procedure must be followed:
1. In the same operation, write a logic one to WDCE and WDE. A logic one must be
2. Within the next four clock cycles, write a logic 0 to WDE. This disables the
In safety level 2, it is not possible to disable the Watchdog Timer, even with the algo-
rithm described above. See “Timed Sequences for Changing the Configuration of the
Watchdog Timer” on page 45.
• 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
Timeout Periods are shown in Table 21.
Table 21. Watchdog Timer Prescale Select
Note:
WDP2
0
0
0
0
1
1
1
1
written to WDE even though it is set to one before the disable operation starts.
Watchdog.
Also see Figure 191 on page 332.
WDP1
0
0
1
1
0
0
1
1
WDP0
0
1
0
1
0
1
0
1
Oscillator Cycles
Number of WDT
1,024K cycles
2,048K cycles
128K cycles
256K cycles
512K cycles
16K cycles
32K cycles
64K cycles
Typical Time-out
at V
15.4 ms
30.8 ms
61.6 ms
0.12 s
0.25 s
0.49 s
CC
1.0 s
2.0 s
= 3.0V
Typical Time-out
at V
14.7 ms
29.3 ms
58.7 ms
2514P–AVR–07/06
0.12 s
0.23 s
0.47 s
CC
0.9 s
1.9 s
= 5.0V