File content as of revision 4:9cc2653d3e83:

#include "mbed.h"
#include "SimpleDMA.h"
#include "dmaSPIslave.h"
#define PAYLOAD_LENGTH 6723
     #define PAY_SPI_MOSI PTE18
    #define PAY_SPI_MISO PTE19
    #define PAY_SPI_CLK PTE17
    #define PAY_SPI_CS PTE16
Timer T;
dmaSPISlave spi(PAY_SPI_MOSI, PAY_SPI_MISO, PAY_SPI_CLK, PAY_SPI_CS);
RawSerial pc(USBTX, USBRX);
DigitalOut ledg(PTB11);

bool flag = false;

void do_this(void){
    flag = true;
}

int main(){
    pc.baud(1200);
    pc.printf("inside main\r\n");
    spi.format(8,0);
    spi.frequency(1000000);
    
    uint8_t buffer[PAYLOAD_LENGTH] = {0};
    pc.printf("welcome to dma test, start sending data now\r\n");

//    initialise the buffer for dma
    spi.bulkRead_init(buffer, PAYLOAD_LENGTH, &do_this);
//    start dma read
    spi.bulkRead_start();
    T.start();
    while(true){
        if(flag){
            flag = false;
            ledg = !ledg;
            pc.printf("re %f\n",T.read());
            /*for(int i = 0 ; i < PAYLOAD_LENGTH ; ++i){
                pc.printf("%02x ", buffer[i]);
            }
            pc.printf("\r\n");*/

//            start dma again after handling the data
            spi.bulkRead_start();
        }
    }
    
}