File content as of revision 1:256d7a2f8391:

#include "mbed.h" 
 
int main() {
    // NOTE: 24MHz is half the 48MHz clock rate.  The PWM registers
    //       seem to only allow 24MHz at this point, so I'm matching
    //       the SPI bus speed to be the same.
    //
    //       1/24MHz  =>  1/(24*10^6)  =>  41.6*10^-9 second period,
    //       which means 41.6ns period and 20.8ns pulse width at
    //       50% duty cycle (which seems to be right for the SPI clock
    //       line as well as a reasonable choice for the PWM line).


    /////////////////////////////////////////////////
    //              SPI SETUP
    /////////////////////////////////////////////////
    // We are not using MISO, this is a one-way bus
    //SPI device(SPI_MOSI, NC, SPI_SCK);

    // Note: Polarity and phase are both 0 for the TC62D723FNG
    // For a graphical reminder on polarity and phase, visit:
    //     http://www.eetimes.com/document.asp?doc_id=1272534
    //
    //device.format(16, 0);
    //device.frequency(24000000); // 24 MHz
    //device.frequency(1000000); // 1 MHz
    /////////////////////////////////////////////////



    /////////////////////////////////////////////////
    //               PWMCLK
    /////////////////////////////////////////////////
    //PwmOut pinPWMCLK(D9); // For Nucleo board, not for Redgarden board
    //pinPWMCLK.write(0.5f); // Set to 50% duty cycle for testing


    /////////////////////////////////////////////////
    //              OTHER / DEBUG
    /////////////////////////////////////////////////
    /////////////////////////////////////////////////




    printf("17:22\n");
    //int i = 0;
    while(1) {
        wait_us(50);
        
        // S0 Command: Needs only SCK and SIN (which are SPI_SCK and SPI_MOSI respectively)
        // This is because TRANS can be 0 for this command according to the datasheet
        SPI data(SPI_MOSI, NC, SPI_SCK);
        data.format(16, 0);
        data.frequency(1000000); // 1 MHz
        data.write(0xFF);
    
        // S1 Command: TRANS / "LATCH"
        // The S1 command doesn't use SIN, but TRANS needs to be on for exactly
        // three clock pulses.  The easiest way to do this is re-configuring
        // the SPI bus to use the TRANS line as MOSI and sending 0x07.  If this
        // doesn't work, we need to bitbang it.
        SPI latch(PA_9, NC, SPI_SCK);
        latch.format(16, 0);
        latch.frequency(1000000); // 1 MHz        
        latch.write(0x07); // Three clock pulses
    }
}