ATTINY44A-MU Atmel, ATTINY44A-MU Datasheet - Page 57

• Manufacturer Part Number: ATTINY44A-MU
• Description: IC MCU AVR 4K FLASH 20MHZ 20QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY44A-MU

• 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: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 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: 20-MLF®, QFN
• Processor Series: ATTINY4x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI/USI
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 20-ch x 10-bit
• Data Rom Size: 256 B
• A/d Bit Size: 10 bit
• A/d Channels Available: 20
• Height: 0.74 mm
• Length: 4 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Width: 4 mm
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• 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