#include <SPI.h>

#define latch 2

void setup() {
  pinMode(latch, OUTPUT);
  SPI.begin();

  digitalWrite(latch, LOW);

  SPI.transfer16(0xf00d);
  SPI.transfer16(0xffff);
  SPI.transfer16(0x5555);

  digitalWrite(latch, HIGH);
}

void loop() {}

 //            v     v
 //Pins 50,   51,    52 and 53    can be configured as SPI 
 //pins MISO, MOSI, SCK and SS    respectively