I have a code with a connection to serial port:
// Set baud rate
UBRR0H = UBRRH_VALUE;
UBRR0L = UBRRL_VALUE;
// Disable USART rate doubler (arduino bootloader leaves it enabled...)
UCSR0A &= ~(1 << U2X0);
// Set async, no parity, 1 stop, 9bit
UCSR0C = (0<<UMSEL01)|(0<<UMSEL00)|(0<<UPM01)|(0<<UPM00)|(0<<USBS0)|(1<<UCSZ01)|(1<<UCSZ00);
UCSR0B |= (1<<UCSZ02); // 9bit
// Enable rx/tx
UCSR0B |= (1<<RXEN0)|(1<<TXEN0);
I see the comments but I want to know exactly what does these chunks means. Is there any complete documentation about these symbols?