Increase of a Non-Volatile RAM Lifetime
Original Publication Date: 1988-Mar-01
Included in the Prior Art Database: 2005-Feb-14
Non-volatile random-access memories (NV RAMs) are used in modems for storing vital information, such as the modem configuration or the telephone numbers for automatic calling in case of switching on the public switching network. A NV RAM is generally comprised of a classical RAM and a read-only memory (ROM) of the same capacity. For the write operation, the information is first written into the RAM before being copied into the ROM by a command STORE. For the read operation, the information contained in the ROM is first copied into the RAM by a command RECALL before being read from the RAM. Unfortunately, due to the NV RAM technology, the failure rate increases as the number of commands STORE increases. Therefore, the total number of STOREs to be applied must be limited if a good level of reliability is to be met.