3 Replies Latest reply on Apr 11, 2017 8:28 AM by phillip.emmett_2375286

    S25FL127S Locking up on Erase

    phillip.emmett_2375286

      I have an Arm processor booting from an S25FL127S and I've seen two apparent failures of the flash. Both follow a similar pattern; they randomly stopped booting under benign conditions (no erase/programming occurring). Using JTAG to read out the flash contents shows no corruption, but attempting to erase the chip (with the intent of reflashing the contents) causes the chip to lockup hard. It can't be accessed again until a power cycle. It also appears to hold the QSPI bus lines, preventing access to a secondary QSPI flash chip. I can't say why the processor can not boot from the chip when JTAG shows the read works but the hard lockup on erase is definitely bad and may indicate what's wrong with the read also. Any ideas why an S25FL127S would lockup on an erase?

        • 1. Re: S25FL127S Locking up on Erase
          gsns

          Hello Philip,

             

          Which you mode you are working Quad IO mode or Single IO mode ? what is the frequency of operation ?

             

          You have observed this on two S25FL127S flash devcies. Am I correct ? After the power cycle there is no problem with booting proves. Is my understanding correct ?

             

          Thanks,

             

          Krishna.

          • 2. Re: S25FL127S Locking up on Erase
            phillip.emmett_2375286

            Should be in QuadIO and a bus frequency of 100mhz.

               

            And yes, two S25FL127S chips on different boards. The power cycle "unjams" the SPI bus and lets me talk to the chip again but it doesn't fix anything. It still can't be booted from and if I attempt to erase it again, it jams again. It's a permanent failure. I can't explain why I can read the chip with JTAG but the processor can not boot from it. The first time this happened I made some tweaks and booted into uBoot from a secondary flash chip. It had the same problems erasing the chip, so it's not limited to the JTAG.

            • 3. Re: S25FL127S Locking up on Erase
              gsns

              Hello Philip,

                 

              Can you please  check block lock status bits in Status Register if they were accidentally set.

                 

              Thanks,

                 

              Krishna.