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// Function to initialise uart interface of AVR
//
// Calling Sequence
// u8AVRUARTSetups(uint8 mode, uint8 baudrate, uint8 stopbits, uint8 parity)
//
// Parameters
// mode : Mode of usart interface (0-Normal mode, 1-Double speed mode,
// 2-Synchronous master mode)
// baudrate : Baudrate for communication. Refer AVRPeripheralUART.h
// for available options)
// stopbits : No. of stopbits (0-1) for stopbits 1 and 2 resp.
// parity: set parity bit. (0-disabled, 1-Even parity, 2-Odd parity)
//
//
// Description
// This function initialises uart interface for AVR. Available modes are
// Normal mode (0), Double speed mode (1), Synchronous master mode(2). 'baudrate'
// decides baudrate for communication. For baudrate settings, variable
// 'XTAL_FREQUENCY' is required. 'stopbits' sets no of stopbits for data
// packet. 0 for 1 stopbit and 1 for 2 stopbits. 'parity' decides parity bit
// for communication. 0 for disabling parity bit, 1 for even parity and 2
// for odd parity.
//
// Authors
// Siddhesh Wani
//
#include "AVRPeripheralUART.h"
uint8 u8AVRUARTSetups(uint8 mode, uint8 baudrate, uint8 stopbits, uint8 parity)
{
switch (mode) //According to mode set bits UMSEL and U2X
{
case 0: //Normal mode
UCSRC &= ~(1<<6); //Clear bit 6 UMSEL
break;
case 1: //Double speed mode
UCSRC &= ~(1<<6); //Clear bit 6 UMSEL
break;
case 2: //Synchronous master mode
UCSRC |= (1<<6); //Set bit 6 UMSEL
break;
}
if(stopbits == 0)
{ // 1 stopbit
UCSRC &= ~(1<<3);
}
else
{ // 2 stopbits
UCSRC |= (1<<3);
}
//Set parity bit settings
switch(parity)
{
case 0: // Parity disabled
UCSRC &= ~(3<<4); //UPM1:0=0
break;
case 1:// Even parity
UCSRC |= (1<<5); //UPM1:0 = 2
UCSRC &= ~(1<<4);
break;
case 2:// Odd parity
UCSRC |= (1<<5); //UPM1:1 = 3
UCSRC |= (1<<4);
break;
}
//Set baud rate
# define BAUD baudrate
#include "util/setbaud.h"
UBRRH = UBRRH_VALUE;
UBRRL = UBRRL_VALUE;
#if USE_2X
UCSRA |= (1 << U2X);
#else
UCSRA &= ~(1 << U2X);
#endif
return 0;
}
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