How can i get 'Hey Cortana' in my lumia 520?

I got an update of lumia denim. But i cant find Hey Cortana in my phone. Can any one say 'Hey Cortana' is available on lumia 520 or not?

Hey cortana is NOT available for the lumia 520 also not with the Demin update. Only phones with a snapdragon 800 chips set can have Hey cortana. (9030, 1520 ICON)

^^What he said^^