According to technical marketing manager Ian Wilson, Intel Corp’s new Flash memory device, the 28F001BX Boot Block (CI No 1,672), is a step nearer taking market share away from the manufacturers of conventional EPROM. Not that Intel doesn’t support EPROM – after all, of course, it makes the chips itself. But Intel has recently made […]
According to technical marketing manager Ian Wilson, Intel Corp’s new Flash memory device, the 28F001BX Boot Block (CI No 1,672), is a step nearer taking market share away from the manufacturers of conventional EPROM. Not that Intel doesn’t support EPROM – after all, of course, it makes the chips itself. But Intel has recently made a pledge not to manufacture any EPROM chips beyond the 4M-bit capacity. This move is to demonstrate Intel’s commitment to Flash memory technology – not surprising since Wilson notes that Intel recently signed a manufacturing deal with NMB Semiconductor Co on its 0.8 micron process in which Intel will be able to fabricate both 4M-bit and 8M-bit Flash memory chips for sampling next year. What is new about the 28F001BX is that it is developed specifically for applications where memory needs to be updated without affecting critical boot code.
The Boot Block Flash consists of a hardware-protected block for storage of critical boot code, and three separately re-programmable blocks, providing the functionality of several components, and meaning that erasing one block doesn’t affect code stored in another block. The blocking scheme of the 28F001BX enables BIOS updates in the main and parameter blocks, and the parameter blocks can be used to back up configuration data stored in static RAM to avoid loss of set-up data when the battery fails. The Boot Block Flash is also suited to embedded applications – such as embedded MS-DOS designs, disk drive controllers, copiers and portable equipment, where integration of chip functions and savings on chip count, board space, power consumpion and product costs are a main concern. The non-volatile memory device, which is manufactured using Intel’s one-micron EPROM tunnel oxide, ETOX II, has a deep power-down mode which lowers power consumption to 10 microWatts when the device isn’t in direct use – says Ian Wilson, this makes the device ideally suited to use in laptops and notebooks. Intel is trying to encourage personal computer users to update and de-bug their BIOSes, something which is possible with this field-upgradable device – instead of having to replace the whole device, when BIOS is stored in EPROM or ROM, users can now upgrade their BIOS by simply changing a floppy. For this reason, says Intel, several personal computer OEM customers have already been signing orders for the new product. Organised as 128K by 8 bits, the 28F001BX comes with 120ns and 150ns access speeds. It is available in three JEDEC-compatible packages – 32-pin plastic dual in-line pinout, 32-lead thin small outline package and 32-lead plastic leaded chip carrier – which are also backwards-compatible with Intel’s 1M-bit, 512K-bit and 256K-bit Flash Memory footprints, as well as with EPROM and ROM devices. Two memory block configurations are possible – with the boot block at the top or the bottom. The top-boot device is designed for systems using microprocessors or microcontrollers that boot from high memory, including Intel’s 80386, 80486, 80860 and 80960 CA microprocessors and the MCS-186 microcontroller family. And the bottom-boot chip is compatible with microprocessors or microcontrollers that boot from low memory, such as Intel’s 80960 KA/KB and 80960 SA/SB microprocessors and MCS-51 and MCS-196 microcontrollers, as well as Motorola Inc’s 68000 family. – Susan Norris