atmel bubble memory charge pump ddr sdram dataflash delay line memory drum memory dynamic random access memory eprom ferroelectric ram field emission flash memory floating-gate transistor hot carrier injection magnetic core memory magnetoresistive random access memory maxwell technologies microchip technology microcontroller microwire mitsubishi nxp semiconductors nano-ram non-volatile memory opcode phase-change memory plated wire memory programmable metallization cell programmable read-only memory racetrack memory read-only memory renesas technology resistive random-access memory sonos stmicroelectronics samsung electronics seiko instruments selectron tube serial peripheral interface bus static random access memory transistor twin transistor ram twistor memory usb flash drive ultraviolet volatile memory williams tube winbond z-ram