ATTINY2313A-SUR Atmel, ATTINY2313A-SUR Datasheet - Page 43

• Manufacturer Part Number: ATTINY2313A-SUR
• Description: MCU AVR 2KB FLASH 20MHZ 20SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY2313A-SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -

8.4.2
8246A–AVR–11/09
Code Example
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:
Assembly Code Example
C Code Example
WDT_off:
void WDT_off(void)
{
}
a. In the same operation, write a logical one to WDCE and WDE. Even though the
b. Within the next four clock cycles, in the same operation, write the WDP bits as
wdr
; Clear WDRF in MCUSR
ldi
out
; Write logical one to WDCE and WDE
; Keep old prescaler setting to prevent unintentional Watchdog Reset
in
ori r16, (1<<WDCE)|(1<<WDE)
out WDTCSR, r16
; Turn off WDT
ldi r16, (0<<WDE)
out WDTCSR, r16
ret
_WDR();
/* Clear WDRF in MCUSR */
MCUSR = 0x00
/* Write logical one to WDCE and WDE */
WDTCSR |= (1<<WDCE) | (1<<WDE);
/* Turn off WDT */
WDTCSR = 0x00;
1. See “Code Examples” on page 6.
WDE always is set, the WDE must be written to one to start the timed sequence
desired, but with the WDCE bit cleared. The value written to the WDE bit is
irrelevant
r16, WDTCSR
r16, (0<<WDRF)
MCUSR, r16
(1)
(1)
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