ATTINY261A-MN Atmel, ATTINY261A-MN Datasheet - Page 44

• Manufacturer Part Number: ATTINY261A-MN
• Description: IC MCU AVR 2K FLASH 32QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY261A-MN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• 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
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Processor Series: ATtiny
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 128 B, 256 B, 512 B
• Interface Type: SPI, USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 2
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 105 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.4.2
44
ATtiny261A/461A/861A
Code Examples
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
1. In the same operation, write a logical one to WDCE and WDE. Even though the WDE
2. Within the next four clock cycles, in the same operation, write the WDP bits as desired,
WDT_off:
void WDT_off(void)
{
}
always is set, the WDE must be written to one to start the timed sequence.
but with the WDCE bit cleared. The value written to the WDE bit is irrelevant.
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;
See
“Code Examples” on page
r16, WDTCSR
r16, (0<<WDRF)
MCUSR, r16
6.
8197B–AVR–01/10