Микроконтроллеры

// for U2X=0, normal speed
#define BAUD_DIV ( ( OSC_HZ + 8*BAUD ) / (16*BAUD) -1 )

void PktInit(void ) {
    UCSR0A = 0;       // U2X0=0, MPCM0=0
    // async, no parity, 1 stop bit, 8 data bits
    UCSR0C = _BV(UCSZ1)|_BV(UCSZ0); 
    UCSR0B = 0;   // disable all UART activity, 8 data bits
    UBRR0L = (u08)BAUD_DIV;
    UBRR0H = (u08)(BAUD_DIV>>8);
    // UDRIE = 0, will be set by PostPacket
    UCSR0B = _BV(RXCIE)|_BV(RXEN)|_BV(TXEN);