ATTINY24A-MUR Atmel, ATTINY24A-MUR Datasheet - Page 57

• Manufacturer Part Number: ATTINY24A-MUR
• Description: MCU AVR 2KB FLASH 20MHZ 20QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY24A-MUR

• 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: 12
• 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 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.1.7
8183C–AVR–03/11
Program Examples
important, it is recommended to use an external pull-up or pulldown. Connecting unused pins
directly to V
accidentally configured as an output.
The following code example shows how to set port A pins 0 and 1 high, 2 and 3 low, and define
the port pins from 4 to 5 as input with a pull-up assigned to port pin 4. The resulting pin values
are read back again, but as previously discussed, a nop instruction is included to be able to read
back the value recently assigned to some of the pins.
Note:
Note:
Assembly Code Example
C Code Example
unsigned char i;
...
; Define pull-ups and set outputs high
; Define directions for port pins
ldi
ldi
out
out
; Insert nop for synchronization
nop
; Read port pins
in
...
...
/* Define pull-ups and set outputs high */
/* Define directions for port pins */
PORTA = (1<<PA4)|(1<<PA1)|(1<<PA0);
DDRA = (1<<DDA3)|(1<<DDA2)|(1<<DDA1)|(1<<DDA0);
/* Insert nop for synchronization*/
_NOP();
/* Read port pins */
i = PINA;
...
Two temporary registers are used to minimize the time from pull-ups are set on pins 0, 1 and 4,
until the direction bits are correctly set, defining bit 2 and 3 as low and redefining bits 0 and 1 as
strong high drivers.
See
CC
“Code Examples” on page
r16,(1<<PA4)|(1<<PA1)|(1<<PA0)
r17,(1<<DDA3)|(1<<DDA2)|(1<<DDA1)|(1<<DDA0)
PORTA,r16
DDRA,r17
r16,PINA
or GND is not recommended, since this may cause excessive currents if the pin is
6.
ATtiny24A/44A/84A
57