gistfile1.txt

#include "SPI.h" // include the SPI library:

#define SPI_TCR 0x60
#define SPI_TDR 0x64
#define SPI_RSR 0x70
#define SPI_RDR 0x74
#define mmio32(x) (*(volatile unsigned long *)(0x403A0000 + x))

#define PAYLOAD 5096
uint16_t dac[PAYLOAD];

void setup()
{
  // set the slaveSelectPin as an output:
  pinMode(6, OUTPUT);
  // initialize SPI:
  SPI.begin();
  SPI.beginTransaction(SPISettings(32000000, LSBFIRST, SPI_MODE0));
  for (int i = 0; i < PAYLOAD; i++)
  {
    dac[i] = i % 0xFFFF;
  }
}


void loop()
{
  mmio32(SPI_TCR) = (mmio32(SPI_TCR) & 0xfffff000) | LPSPI_TCR_FRAMESZ(15); // turn on 16 bit mode

  digitalWriteFast(6, LOW);
  for (int i = 0; i < PAYLOAD; i++)
  {
    mmio32(SPI_TDR) = dac[i]; // output 16 bit data.
    digitalWriteFast(6, LOW);
    //while ((mmio32(SPI_RSR) & LPSPI_RSR_RXEMPTY)) ;	// wait while the RSR fifo is empty...
    delayNanoseconds(560);
   volatile int junk = mmio32(SPI_RDR);
    digitalWriteFast(6, HIGH);
  }
  digitalWriteFast(6, HIGH);
  delay(10);
}