EAROM and EEPROM data storage management

• US 4,638,430 A
• Filed: 07/15/1983
• Issued: 01/20/1987
• Est. Priority Date: 07/15/1983
• Status: Expired due to Fees

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Wilmot, Stephen B., Perra, Raymond C., Games, John E.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Fairbanks, Jonathan C.
• Application Number:
  US06/514,214
• Time in Patent Office: 1,285 Days
• Field of Search: 360/5, 360/6, 360/53, 360/60, 364/178, 364/179, 364/200 MS File, 364/900 MS File, 364/424, 364/300, 365/31, 365/96, 365/228, 365/229, 371/10, 371/11, 371/21, 371/4, 244/96, 244/175
• US Class Current: 711/103
• CPC Class Codes: G06F 16/901 Indexing; Data structures therefor; Storage structures for retrieval from the web G06F16/951
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 16/3495 Circuits or methods to detect or delay wearout of nonvolatile EPROM or EEPROM memory devices, e.g. by counting numbers of erase or reprogram cycles, by using multiple memory areas serially or cyclically

Abstract

Recurring data sample values of a common parameter are stored in nonvolatile memory at different addresses so as to limit the maximum number of entries at any one location to less than that which results in loss of storage ability.

Claims

1. A method of recording successive values of high sample frequency parameters in a nonvolatile memory having a plurality of addressable signal storage locations for storing digital data recorded therein over a maximum number of recording cycles, comprising the steps of:

identifying a data signal block for each high sample frequency parameter as including a plurality of addressable storage locations at least equal to the ratio of the predicted number of recordings of each high sample frequency parameter in a selected lifetime interval, divided by the maximum number of recording cycles specified for each location; and

recording successive values of sample data in alternate ones of the data block signal locations so as to limit the number of recordings in each location to a number which is not greater than the maximum number of recording cycles specified.

2. The method of claim 1 wherein the step of recording each sample value includes the first step of pointing to the particular one of the addressable locations within the associated data signal block at which a present sample value is to be recorded, the particular pointed address being any one of said data block storage locations having less than said maximum specified number of recordings.

3. The method of claim 2, wherein said step of pointing identifies succeeding addressable storage locations for recording succeeding sample values of an associated data signal block, from a first location to a last location, in each of a number of recurring cycles equal to or less than the maximum specified for each location.

4. The method of claim 2, wherein said step of pointing identifies each data signal block storage location for recording, in turn, consecutive sample data values in each of a number of recurring cycles up to the maximum specified for each location, and if less than the maximum number is recorded at each location than to repeat the identification of each location in succesive cycles.