spi.c

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#include <app.h>

volatile bit gSpiTx=CLEAR; 
volatile bit gSpiRx=CLEAR;
void SPI_Init(void) 
{
    SSPEN = DISABLE; // Reset

    TRISC4 = DIR_IN; // SPI Slave In
    TRISC5 = DIR_OUT; // SPI Slave Out
    TRISC3 = DIR_OUT; // SPI Slave CLK Out
    //  TRISA5 = DIR_IN;   // SPI SS Enabled In, used for other purpose then SPI

    SMP = CLEAR; // Input data at middle (compat=0)

    SSPM0 = CLEAR; // Clock /4 
    SSPM1 = CLEAR;
    SSPM2 = CLEAR;
    SSPM3 = CLEAR;

    CKP = SET; // Clock idle is high
    CKE = CLEAR; // Data on rising edge (compat=1)

    SSPEN = ENABLE; // SPI port pins enabled
    SSPIE = ENABLE; // Enable interrupt on SPI receiving
    PEIE = ENABLE; // Enable peripherial interrupt(For SPI)
}
BYTE SPI_Exchange(BYTE data) 
{
    BYTE rxdata;
    rxdata = SSPBUF; // lose any data in buffer, clear BF
    SSPBUF = data;
    while (!BF) continue;
    CLRWDT();
    return SSPBUF;
}
void SPI_Write(BYTE data) 
{
    gSpiTx = 1;
    SPI_Exchange(data);
    while (gSpiTx);
}
BYTE SPI_Read(void) 
{
    BYTE in;
    gSpiRx = 0;
    in = SPI_Exchange(0x00);
    while (!gSpiRx);
    return in; // get received data, clear BF 
}

//*********************************************************[ENDL]***************