M24LR EEPROM write cycle endurance?

[Derick Cochrane]

Posted on November 06, 2017 at 10:24

Hello,

I am working on a project is using the M24LR NFC device as an intermediate Communication device between a target temperature sensing MCU and the CR95HF reader. We do not require a 'high bandwidth' throughput, only occasionally will we need to transmit data through the M24LR 'RF visible' eeprom memory. We would like to know if we need to employ Forward Error Correction with our data packets as we are unsure of the reliability of the EEPROM. The data sheet quotes a 'max write endurance cycle endurance' of 1,000,000 cycles. Does this figure mean that 1,000,000 erase/write cycles can be performed to an eeprom block (4 bytes) BEFORE a single failure is expected to occur? Do we need a FEC system at all? Should we employ a 'wear leveling' technique to cycle through memory rather than writing to the same area continuously? Any clarification on this matter would be appreciated.

Many thanks,

Derick

#nfc-tag-type-5

[JL. Lebon · Accepted solution]

Posted on December 20, 2017 at 14:52

Dear Derick,

The 'maximum write cycle endurance' of 1,000,000 cycles, as written in the datasheet, means the maximum write cycling values for one memory cell (write is not guaranteed above this threshold).

1 write cycle means the writing of 1 Byte, 2 Bytes, 3 Bytes or 4 Bytes (1 page) simultaneous.

If the total number of write cycles for a cell is below the max write cycling values, data can be written without any constraint. Otherwise, specific writing procedure should be used (data reallocation strategy).

Please be aware that the 1,000,000 cycles value is given for an operating temperature of 25 degrees Celsius. Cycling endurance is decreasing when temperature is rising. For instance, max cycling endurance is reduced to 150k writes at 85C.

Best regards.