ATtiny13A Atmel Corporation, ATtiny13A Datasheet - Page 40

• Manufacturer Part Number: ATtiny13A
• Manufacturer: Atmel Corporation

Specifications of ATtiny13A

• Flash (kbytes): 1 Kbytes
• Pin Count: 8
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 6
• Ext Interrupts: 6
• Usb Speed: No
• Usb Interface: No
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.06
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 125
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 1
• Output Compare Channels: 2
• Pwm Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

40
ATtiny13A
The following code example shows one assembly and one C function for turning off the Watch-
dog Timer. The example assumes that interrupts are controlled (e.g. by disabling interrupts
globally) so that no interrupts will occur during the execution of these functions.
Note:
If the Watchdog is accidentally enabled, for example by a runaway pointer or brown-out condi-
tion, the device will be reset and the Watchdog Timer will stay enabled. If the code is not set up
to handle the Watchdog, this might lead to an eternal loop of time-out resets. To avoid this situa-
Assembly Code Example
C Code Example
WDT_off:
void WDT_off(void)
{
}
; Turn off global interrupt
cli
; Reset Watchdog Timer
wdr
; Clear WDRF in MCUSR
in
andi
out
; Write logical one to WDCE and WDE
; Keep old prescaler setting to prevent unintentional time-out
in
ori
out
; Turn off WDT
ldi
out
; Turn on global interrupt
sei
ret
__disable_interrupt();
__watchdog_reset();
/* Clear WDRF in MCUSR */
MCUSR &= ~(1<<WDRF);
/* Write logical one to WDCE and WDE */
/* Keep old prescaler setting to prevent unintentional time-out */
WDTCR |= (1<<WDCE) | (1<<WDE);
/* Turn off WDT */
WDTCR = 0x00;
__enable_interrupt();
See
“Code Examples” on page
r16, MCUSR
r16, (0xff - (1<<WDRF))
MCUSR, r16
r16, WDTCR
r16, (1<<WDCE) | (1<<WDE)
WDTCR, r16
r16, (0<<WDE)
WDTCR, r16
6.
8126E–AVR–07/10