ATMEGA3250-16AUR Atmel, ATMEGA3250-16AUR Datasheet - Page 46

• Manufacturer Part Number: ATMEGA3250-16AUR
• Description: MCU AVR 32K FLASH 16MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K 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: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.9
2570M–AVR–04/11
Timed Sequences for Changing the Configuration of the Watchdog Timer
Table 10-2.
The following code example shows one assembly and one C function for turning off the WDT.
The example assumes that interrupts are controlled (e.g. by disabling interrupts globally) so that
no interrupts will occur during execution of these functions.
Note:
The sequence for changing configuration differs slightly between the two safety levels. Separate
procedures are described for each level.
WDP2
Assembly Code Example
C Code Example
0
0
0
0
1
1
1
1
WDT_off:
void WDT_off(void)
{
}
; Reset WDT
wdr
; Write logical one to WDCE and WDE
in
ori r16, (1<<WDCE)|(1<<WDE)
out WDTCR, r16
; Turn off WDT
ldi r16, (0<<WDE)
out WDTCR, r16
ret
/* Reset WDT */
__watchdog_reset();
/* Write logical one to WDCE and WDE */
WDTCR |= (1<<WDCE) | (1<<WDE);
/* Turn off WDT */
WDTCR = 0x00;
1. See
WDP1
0
0
1
1
0
0
1
1
r16, WDTCR
Watchdog Timer Prescale Select
“About Code Examples” on page
(1)
WDP0
0
1
0
1
0
1
0
1
(1)
Oscillator Cycles
Number of WDT
1,024K cycles
2,048K cycles
128K cycles
256K cycles
512K cycles
16K cycles
32K cycles
64K cycles
ATmega325/3250/645/6450
9.
Typical Time-out
at V
17.1ms
34.3ms
68.5ms
0.14s
0.27s
0.55s
CC
1.1s
2.2s
= 3.0V
Typical Time-out
at V
16.3ms
32.5ms
65ms
0.13s
0.26s
0.52s
CC
1.0s
2.1s
= 5.0V
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