getsuart1.c

Microchip的官方PIC24H系列16位单片机的外设源程序库。

#include<uart.h>
#include<p30fxxxx.h>

/****************************************************************************
* Function Name     : getsUART1
* Description       : This function gets a string of data of specified length  
*                     if available in the UxRXREG buffer into the buffer 
*                     specified.
* Parameters        : unsigned int length the length expected
*                     unsigned int *buffer  the received data to be 
*                                  recorded to this array
*                     unsigned int uart_data_wait timeout value
* Return Value      : unsigned int number of data bytes yet to be received
*************************************************************************/

unsigned int getsUART1(unsigned int length,unsigned int *buffer,
                       unsigned int uart_data_wait)
{
    int wait = 0;
    char *temp_ptr = (char *) buffer;

    while(length)                         /* read till length is 0 */
    {
        while(!DataRdyUART1())
        {
            if(wait < uart_data_wait)
                wait++ ;                  /*wait for more data */
            else
                return(length);           /*Time out- Return words/bytes to be read */
        }
        wait=0;
        if(U1MODEbits.PDSEL == 3)         /* check if TX/RX is 8bits or 9bits */
            *buffer++ = U1RXREG;          /* data word from HW buffer to SW buffer */
	else
            *temp_ptr++ = U1RXREG & 0xFF; /* data byte from HW buffer to SW buffer */

        length--;
    }

    return(length);                       /* number of data yet to be received i.e.,0 */
}