Exactly how much is endurance?

[PRana.3]

Hi

We are using 95128-A125. It's datasheet provides "write cycle endurance" numbers for various operating temperatures. But there is a note that reads "The Write cycle endurance is defined for groups of four data bytes located at addresses [4*N, 4*N+1, 4*N+2, 4*N+3] where

N is an integer, or for the status register byte". Is the "status register byte write" considered as one write cycle regardless of address? For writing to any location within the EEPROM, we have to write to status register first (to set the bit WEL). Suppose we perform the following steps:

1. Write to status register to set WEL, then write 32 bit data at address 0x0000.
2. Write to status register to set WEL, then write 32 bit data at address 0x0010.
3. Write to status register to set WEL, then write 32 bit data at address 0x0020.

Q1: How many write cycles will be counted for address 0x0000? One? or two (because we wrote into the status register AND wrote to address 0x0000)?

Q2: Since we wrote 3 times into the status register (but for different addresses): will that be counted as 3 write cycles for any address? I mean, if we write 100K times each in 40 different locations: will that exhaust the endurance of 4M because we wrote into the status register 4M times?

Regards,

Pramod Ranade

[Pierre P. · Accepted solution]

Hello,

Status register is a specfic area outside the memory location. During a Write status register command, you don't have the choice of the address.

Each write the status register instruction is counted as 1 write cycle.

WREN command (so setting the WEL bit to 1) is not considered as a write status register so it's not considered as a write cycle.

Answer to Q1 : One write cyle.

Answer to Q2 : One write status register command (not a WREN) is equivalent to one write cycle.

Best Regards

Team EEPROM SuPPort

[PRana.3]

Thank you @Pierre P.​ for the clear answer!

Regards,

Pramod Ranade