File content as of revision 1:21efeeb9b679:

#include "mbed.h"

SPI spi(PTD6, PTD7, PTD5); // mosi, miso, sclk
DigitalOut cs(D9);


int main() 
{
 
 
 
   // Setup the spi for 8 bit data, high steady state clock,
    // second edge capture, with a 1MHz clock rate
    spi.format(8,3);
    spi.frequency(3000000);

    cs = 0;
    spi.write(0x80);  // set write register to seconds
    spi.write(0x01);  // send value of zero
    
    cs=1;
    cs=0;
     spi.write(0x81);  
    spi.write(0x58);   //write reg to minutes
    
    cs=1;
    cs=0;
    
    spi.write(0x82);  
    spi.write(0x01);  //write reg to hours (00-23)
    
    cs=1;
    cs=0;
    
    spi.write(0x83);  
    spi.write(0x01);  //write reg to day (1-7)
    
    cs=1;
    cs=0;
    
    spi.write(0x84);  
    spi.write(0x01);  //write reg to date(01-31)
    
    cs=1;
    cs=0;
    
    spi.write(0x85);  
    spi.write(0x01);  //write reg to mnth(01-12)
    
    cs=1;
    cs=0;
    
    spi.write(0x86);  
    spi.write(0x01);  //write reg to year(00-99)

    cs=1;
    // Receive the contents of the seconds register
   
   for(int i=0;i<1000000;i++){
    
        
    cs=0;
    spi.write(0x00);                 // set read register to seconds
    int seconds = spi.write(0x00);   // read the value by sending dummy byte
    
    cs=1;
    cs=0;
    
    spi.write(0x01);
    int minutes =spi.write(0x01);
    
    cs=1;
    cs=0;
    
    spi.write(0x02);
    int hours =spi.write(0x01);
    
    cs=1;
    cs=0;
    
    spi.write(0x03);
    int day =spi.write(0x01);
    
    cs=1;
    cs=0;
    
    spi.write(0x04);
    int date =spi.write(0x01);
    
    cs=1;
    cs=0;
    
    spi.write(0x05);
    int mnth =spi.write(0x01);
    
    cs=1;
    cs=0;
    
    spi.write(0x06);
    int year =spi.write(0x01);
    
    //This cs=1 is to make the chipselect line high to "deselect" the slave in our case RTC
    cs = 1;
    
    //This printf function is to check the timestamp function in the terminal output
    printf("timestamp as  = %X : %X : %X : %X : %X : %X : %X\n\r", year,mnth,date,day,hours,minutes,seconds);
    }
    
    
    
    return 0;
    
    }