ATTINY13-20PJ Atmel, ATTINY13-20PJ Datasheet - Page 40

• Manufacturer Part Number: ATTINY13-20PJ
• Description: IC MCU AVR 1K 5V 20MHZ 8DIP
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY13-20PJ

• 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-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Connectivity: -
• Other names: ATTINY13-24PJ; ATTINY13-24PJ

40
ATtiny13
tion, the application software should always clear the Watchdog System Reset Flag (WDRF)
and the WDE control bit in the initialisation routine, even if the Watchdog is not in use.
The following code example shows one assembly and one C function for changing the time-out
value of the Watchdog Timer.
Note:
The Watchdog Timer should be reset before any change of the WDP bits, since a change in the
WDP bits can result in a time-out when switching to a shorter time-out period.
Assembly Code Example
C Code Example
WDT_Prescaler_Change:
void WDT_Prescaler_Change(void)
{
}
; Turn off global interrupt
cli
; Reset Watchdog Timer
wdr
; Start timed sequence
in
ori
out
; --
; Set new prescaler(time-out) value = 64K cycles (~0.5 s)
ldi
out
; --
; Turn on global interrupt
sei
ret
__disable_interrupt();
__watchdog_reset();
/* Start timed sequence */
WDTCR |= (1<<WDCE) | (1<<WDE);
/* Set new prescaler(time-out) value = 64K cycles (~0.5 s) */
WDTCR = (1<<WDE) | (1<<WDP2) | (1<<WDP0);
__enable_interrupt();
1. The example code assumes that the part specific header file is included.
r16, WDTCR
r16, (1<<WDCE) | (1<<WDE)
WDTCR, r16
Got four cycles to set the new values from here -
r16, (1<<WDE) | (1<<WDP2) | (1<<WDP0)
WDTCR, r16
Finished setting new values, used 2 cycles -
(1)
(1)
2535J–AVR–08/10