File content as of revision 0:0b1ae70a694b:

#include "mbed.h"
#include "rtos.h"
#include "ExioMcp23s17.h"

SPI Spi(PC_12, PC_11, PC_10); // SPI3: mosi, miso, sclk
//SPI Spi(PA_7, PA_6, PA_5); // SPI1:  mosi, miso, sclk

// MExioMcp23s17(int hardwareaddress, SPI& spi, PinName nCs, PinName nReset);
ExioMcp23s17 Exio(0x00, Spi, PD_2, PA_13);

void ExioMcp23s17Test()
{
    printf("\r\n\n*** ExioMcp23s17 ***\r\n");

    // Reset MCP23S17
    Exio.reset();
    
    // PORTA output
    Exio.ioDirection(ExioPortA, 0x00);

    // PORTB input
    Exio.ioDirection(ExioPortB, 0xFF);
    // PORTB pull-up
    Exio.ioPullup(ExioPortB, 0xFF);
    // PORTB invert polarity
    Exio.ioPolarity(ExioPortB, 0xFF);
    
    // LED Check
    for (int i = 0; i < 8; i++) {
        Exio.writePort(ExioPortA, 1 << i);
        wait(0.1);
    }
    Exio.writePort(ExioPortB, 0x00);
    
    while (true) {
        char data = Exio.readPort(ExioPortB);
        wait_us(1);
        Exio.writePort(ExioPortA, data);
    }
}

int main()
{
    ExioMcp23s17Test();
}