SPI source code

Check even bij infineon appnotes

C166 appnotes.

There is a note (and source) how to implement SPI or synchronious serial communication on any pin of a microcontroller.


Bert Regards.

which article can i find the information related to SPI?
And i want to use the basic I/O pin to simulate the spi port.
i can' t find it. PLease Help!

What's the difficulty here? SPI is dead simple. You select the device to talk to via the chip select line, you drive the data on to the data pin, you clock that data pin to the selected device, and finally you de-select that device. E.g.

sbit r_spiClk = 0x90; // Port 1.0
sbit r_spiDat = 0x91; // Port 1.1
sbit r_spiCs0 = 0x92; // Port 1.2 - Slave Device 1
sbit r_spiCs1 = 0x93; // Port 1.3 - Slave Device 2
sbit r_spiCs2 = 0x94; // Port 1.4 - Slave Device 3

typedef unsigned char U8;
typedef bit           Bool;
typedef enum Slaves { SLAVE_DEV_1, SLAVE_DEV_2, SLAVE_DEV_3, NUM_SLAVES } Slaves;

// _____________________________________________________________________________
// _____________________________________________________________________________
//
// Function:  sendSpiMsg
//
// Description:
// ------------
// Sends <len> bytes of <pMsg> to <slave>.
//
// Design Notes:
// -------------
// Returns true for any failure, zero for no failures.
//
// UNTESTED!
// _____________________________________________________________________________
//
Bool sendSpiMsg(U8 *pMsg, U8 len, Slaves slave)
{
    if (slave >= NUM_SLAVES) return 1;

    switch (slave)
    {
        case SLAVE_DEV_1: r_spiCs0 = 0; break;
        case SLAVE_DEV_2: r_spiCs1 = 0; break;
        case SLAVE_DEV_3: r_spiCs2 = 0; break;
    }

    while (len--)
    {
        U8 currentByte = *pMsg++;
        U8 bitCount    = 8;

        while (bitCount--)
        {
            r_spiClk = 1;
#ifdef LSBIT_FIRST
            r_spiDat    = currentByte & 1;
            currentByte = currentByte >> 1 & 0x7F;
#else // MSBit first
            r_spiDat      = currentByte & 0x80;
            currentByte <<= 1;
#endif
            r_spiClk = 0;
        }
    }

    // Leave bus in safe state. Chip selects low active.
    r_spiClk = 1;
    r_spiDat = 1;
    r_spiCs0 = 1;
    r_spiCs1 = 1;
    r_spiCs2 = 1;

    return 0;
}