BareMetal Programming

DDRB | = 1<<5;

• port b pin 5 is set as output

• port b pin 5 is set as input

• port b pin 4 is set as output

• port b pin 4 is set as input

DORD

• Data order bit

• Data Operation Bit

• Data Output Register

• Data Opposite Order

TWI for which communication

• SPI

• UART

• USART

• I2C

UDR

• Upper Data Register

• UART Data Register

• Upper Data Rate Register

• USART Data Rate Register

ACO

• Analog Comparator Output

• Analog Comparator

• Analog Combination Register