ATTINY13-20SSI Atmel, ATTINY13-20SSI Datasheet - Page 39

• Manufacturer Part Number: ATTINY13-20SSI
• Description: IC MCU AVR 1K FLASH 20MHZ 8SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY13-20SSI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 6
• Program Memory Size: 1KB (512 x 16)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 64 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-SOIC (3.9mm Width)
• Data Bus Width: 8 bit
• Data Ram Size: 64 B
• Interface Type: SPI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 4 Channel
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Connectivity: -
• Lead Free Status / Rohs Status: No
• Other names: ATTINY13-24SSI; ATTINY13-24SSI

2535J–AVR–08/10
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();
1. The example code assumes that the part specific header file is included.
r16, MCUSR
r16, (0xff - (1<<WDRF))
MCUSR, r16
r16, WDTCR
r16, (1<<WDCE) | (1<<WDE)
WDTCR, r16
r16, (0<<WDE)
WDTCR, r16
(1)
(1)
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