ATmega6450 Atmel Corporation, ATmega6450 Datasheet - Page 46

• Manufacturer Part Number: ATmega6450
• Manufacturer: Atmel Corporation

Specifications of ATmega6450

• Flash (kbytes): 64 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 69
• Ext Interrupts: 25
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

11.9
2570N–AVR–05/11
Timed Sequences for Changing the Configuration of the Watchdog Timer
Table 11-2.
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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