12 Replies Latest reply on May 15, 2019 2:58 PM by BushraH_91

    Sudden Bad blocks Occurance

    goma_1720936

      Hi,

       

      We are using S34ML01G100BHI000 in our product. In one of the board we have seen sudden increase in bad blocks number (127 bad blocks). We are using the board just for around 3-4 months. We have not seen this issue with other boards which we are using for around 1 year. Could you please let us know if it is possible to have so many bad blocks within such short time duration (3-4 months)?  Can excessive current flow cause this scenario?

      Is there any other possible scenarion which can cause the sudden increase in bad block number?

       

       

        • 1. Re: Sudden Bad blocks Occurance
          BushraH_91

          Hello,

          Thank you for contacting Cypress Community Forum. Currently we are reviewing the issue and will get back to you as soon as we find the resolution.

           

          Have a wonderful day

          Regards,

          Bushra

          • 2. Re: Sudden Bad blocks Occurance
            BushraH_91

            Hello,

            This is very unusual, we don’t expect to see a significant increase in the number of bad blocks.

            How many bad blocks did you have before this sudden increase?

            Any changes on the board in terms of power supply stability?  How many bad blocks?

            Are these bad blocks consecutive? Which blocks?

            Do you see the same bad blocks failing all the time or different blocks?

            Can you erase a “bad block” and see if it is good again?

             

            Please check the voltage stability during power up and during the operation.

             

            Thank you

            Regards,

            Bushra

            • 3. Re: Sudden Bad blocks Occurance
              goma_1720936

              Hi Bushrah,

               

              Thank you for your reply.

               

              Please find my answers inline below –

               

              Thanks,

              Goutam

              • 4. Re: Sudden Bad blocks Occurance
                goma_1720936

                Hi Bushrah,

                 

                Thank you for your reply.

                 

                Please find my answers inline below –

                 

                How many bad blocks did you have before this sudden increase?

                 

                ->I am not sure about the exact number however around 1 month back it was around 3

                 

                Any changes on the board in terms of power supply stability?  How many bad blocks?

                 

                ->There is no change in board in terms of supply stability, however there might be case of static discharge due to wrong handling of the board (Can this cause this type of issue?). Right now it shows around 125 bad blocks.

                 

                Are these bad blocks consecutive? Which blocks?

                 

                ->Not all the blocks are consecutive. They are in bunch it seems. Following is the list of bad block number-

                 

                Block #0

                 

                From block #4 till block #96

                 

                From block #101 till block  #113

                 

                Block #115, block #135, block #141, block #142, block #145, block #175, block #176, block #180, block #192, block #1015, block #1016, block #1018, block #1019, block #1020, block #1021,  block #1022, block #1023

                 

                Do you see the same bad blocks failing all the time or different blocks?

                 

                ->I see the same bad blocks every time.

                 

                Can you erase a “bad block” and see if it is good again?

                 

                ->I tried to erase those bad blocks. However I am getting error while trying to write on them.

                 

                Please check the voltage stability during power up and during the operation.

                 

                -> Yes we will check.

                Thanks,

                Goutam

                • 5. Re: Sudden Bad blocks Occurance
                  BushraH_91

                  Hello,

                  Let us try to run an experiment to understand the failure:

                   

                  Can you read ID after power up?

                  If so, please verify that it is the correct ID.

                   

                  You mentioned that you are failing blocks 4-96 (among others)

                  Can you erase the first five blocks  0-5 and check for FF data to make sure it is erased.

                  Try to program each block separately and see if you pass programming.

                  Please send us the result of the experiment.

                   

                  Thank you

                  Regards,

                  Bushra

                  • 6. Re: Sudden Bad blocks Occurance
                    goma_1720936

                    Hi Bushra,

                     

                    We will perform all the tests mentioned and will get back to you with the results.

                     

                    Thanks,

                    Goutam

                    • 7. Re: Sudden Bad blocks Occurance
                      goma_1720936

                      Hi Bushra,

                       

                      Please find the results of the tests we performed -

                       

                       

                       

                      Can you read ID after power up?

                       

                      -        Yes we can read ID after power up but ID what we are getting is not matching with ID given in datasheet

                       

                      -        Expected according to datasheet : 01 F1 00 1D

                       

                      -        Actual : EF F1 00 95 (1st byte which is Manufacturer code was EFh instead of 01h and 4th byte is 95h instead of 1Dh )

                       

                      Though we are getting the same ID for some other boards we tried.

                       

                       

                      You mentioned that you are failing blocks 4-96 (among others)

                      Can you erase the first five blocks  0-5 and check for FF data to make sure it is erased.

                       

                      -        Yes we are able to erase first five block and confirmed that with reading FF data from those block.

                       

                       

                      Try to program each block separately and see if you pass programming.

                       

                      -        We have tried to program each block by writing dummy data but in return of write api we are getting result as the block being accessed is bad. However when we tried reading the same blocks and got the same dummy data that we have written before.

                      Thanks,

                      Goutam

                      • 8. Re: Sudden Bad blocks Occurance
                        BushraH_91

                        Hello,

                        Thank you for the update. We are looking into the issue. Please bear with us.

                         

                        Have a wonderful day

                        Regards,

                        Bushra

                        • 9. Re: Sudden Bad blocks Occurance
                          BushraH_91

                          Hello,

                          Please refer to comments in red below:

                           

                           

                          "Though we are getting the same ID for some other boards we tried."

                          What do you mean “getting the same ID”, are you getting the expected ID? i.e: 01 F1 00 1D

                          If yes, then the failing part has been compromised/damaged.

                           

                          Thank you

                          Regards,

                          Bushra

                          • 10. Re: Sudden Bad blocks Occurance
                            BushraH_91

                            Hello,

                            Any update? Is your issue resolved?

                             

                            Thank you

                            Regards,

                            Bushra

                            • 11. Re: Sudden Bad blocks Occurance
                              goma_1720936

                              Hi Bushra,

                               

                              Sorry we did not get much time to spend on it. Only thing is we are getting the same ID value (EF F1 00 95) for all other good boards as well. We are also able to read the ONFI parameters from the board with bad block as well.

                              Please let us know if  you need any more information.

                               

                              Thanks,

                              Goutam

                              • 12. Re: Sudden Bad blocks Occurance
                                BushraH_91

                                Hello,

                                Good boards read the correct ID.

                                 

                                Thank you

                                Regards,

                                Bushra

                                 

                                .