US Patent 7154297 Programmable logic with programmable volatility

Volatility of a programmable logic device (PLD) or field programmable gate array (FPGA) is selectable to be volatile or nonvolatile. In the volatile mode, configuration or other data of the integrated circuit are lost once power is removed from the integrated circuit. In the nonvolatile mode, configuration or other data is retained even when power is removed from the integrated circuit. Upon power-up, in nonvolatile mode, the integrated circuit does not need external data. In an embodiment, the mode, whether volatile or nonvolatile, may be selected during manufacturing. In other embodiment, the mode may be selected by other means, such as by the user.