1 Reply Latest reply on Dec 13, 2016 2:12 AM by sdhk

    S25FL256S flash seems to be locked

    alexlee84

      Hi,

         

      During development the Uboot/Linux driver for S25FL256S flash, I encounter a problem that the flash seems to be locked and cannot be reset. Even the JTAG also cannot erase/program the flash, only debug the code in the RAM.  

         

      I tried to read registers, the SR1 = 0x1C, the CR1 = 0xEE. the BPNV bit has been set to 1 and BP2-0 in SR are volatile and will be reset to binary 111 after POR. 

         

      How can I unlock the flash?

        • 1. Re: S25FL256S flash seems to be locked
          sdhk

          Hi,

             

          Did you try to change the value in SR1 and CR1 using WREN and WRR commands?

             

          1. CS# LOW

             

          2. WREN command

             

          3. CS# HIGH

             

          4. CS# LOW

             

          5. WRR command + SR1 value + CR1 value

             

          6. CS# HIGH

             

          Also, please let us know the steps you follow to program and erase flash device.

             

          Thanks and Regards,

             

          Sudheesh