Browse Prior Art Database

Data Protection Method in Flash Memory with Maximum Code Size

IP.com Disclosure Number: IPCOM000123989D
Original Publication Date: 1999-Sep-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 2 page(s) / 83K

Publishing Venue

IBM

Related People

Miyamura, T: AUTHOR

Abstract

A program is disclosed that protects data area in flash memory from accidental corruption with saving maximum code size by sharing one flash memory block between data area and code area.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 60% of the total text.

Data Protection Method in Flash Memory with Maximum Code Size

   A program is disclosed that protects data area in flash
memory from accidental corruption with saving maximum code size by
sharing one flash memory block between data area and code area.

   A flash memory is structured with several blocks.  The
block is a unit to erase flash memory data.  Software can write a
certain value to the empty flash memory area after erasing
corresponding block if any other valid or invalid value exists on it.

   Flash memory is used to save a program code or any
data.  The program code runs from flash memory at power on and
controls a system or a device.  The program code is not updated to
the other code except for an Engineering Changes such as problem
solving or function improvement.  On the other hand, the data is
frequently updated to the latest one by the program code to change
its configuration or log any traced record.  The data is normally
saved in Random Access Memory (RAM) and copied to the flash memory
periodically because the write access times to flash memory is
restricted by the hardware specification.  If a user shuts down the
system or the device while data in RAM is copied to the flash memory,
the data is corrupted.  In order to recover the corrupted data, the
data is stored in two block and saved to each block one by one.  If a
data block is corrupted, the system or the device recovers the
corrupted block at the next boot up.

   Generally speaking, t...