we are working with S25FL132K SPI based NOR flash which we interfaced with LPC1778 uC. Previously it was worked but what was happened we don't know, now it is not retaining the previously saved data, when we remove the power supply. During the power supply ON serial flash writing and reading was working.
when we remove the power supply previously written data was replacing with SFDP registers data.i.e When we give command 0x03 continous read command and from address we are getting SFDP register data.
Before removing the power supply, please ensure that Chip Select is deasserted Logic High, prior to removing the power supply.
This will make certain that the S25FL123K is not selected. As well please make certain that no PROGRAM or ERASE operation
is currently executing when the power supply is removed.
Thank you and regards,
Cypress Technical Support