Abstract: Disabling flash memory cells to protect their contents, and thus essentially transforming them into read-only memory (ROM) cells, is disclosed. A gate mask and an implant code mask are positioned over a given flash memory cell. A field oxide layer is then fabricated within a substrate layer of the cell through the masks as logically and'ed together. By such fabrication, the flash memory cell is at least partially disabled. The masks are preferably a gate mask and an implant code mask, as these masks typically are already existing and available for use.

Abstract: A method for setting system working frequency includes the steps of: executing assert reset; modulating the system working frequency according to set values of BIOS through a jumper-free IC; deasserting reset and starting CPU; and proceeding and completing subsequent initialization process.

Abstract: Disabling flash memory cells to protect their contents, and thus essentially transforming them into read-only memory (ROM) cells, is disclosed. A gate mask and an implant code mask are positioned over a given flash memory cell. A field oxide layer is then fabricated within a substrate layer of the cell through the masks as logically and'ed together. By such fabrication, the flash memory cell is at least partially disabled. The masks are preferably a gate mask and an implant code mask, as these masks typically are already existing and available for use.

Abstract: A new method is provides for the creation of a hardmask over a layer of polysilicon for the etching of floating gate for split-gate flash memory devices. A layer of gate oxide is created over the surface of a substrate, a layer of polysilicon is deposited over the surface of the layer of gate oxide. In a first embodiment of the invention, a layer of native oxide is grown over the surface of the layer of gate material, this layer of gate oxide is used to enhance oxidation of exposed portions of the layer of gate material. In a second embodiment of the invention, enhanced oxidation of exposed portions of the layer of polysilicon is achieved by modifying the conventional sequence of the oxidation process. This latter modification is realized by modifying the forward motion of the substrates through the oxidation furnace or by modifying the sequence in which the substrates move through the oxidation furnace.