three generations,  ST-Ericsson 's Nova and NovaThor, Silicon Labs 's Precision32 MCU,  Texas Instruments 's  OMAP  products, Samsung's Hummingbird and  Exynos  products, Apple's  A4 ,  A5 , and A5X chips, and  Freescale 's  i.MX . Companies can also obtain an ARM  architectural license  for designing their own, different CPU cores using