4 Replies Latest reply on May 26, 2019 7:50 PM by MaMi_1205306

    CY62148G30-45ZSXI ECC function

    MaMi_1205306

      Hi,

       

      CY62148G30 has an ECC function.

       

      Furthermore, This device has not ERR terminal.

       

      What happens if multi-bit error occurs?

       

      However, the data sheet has the following description.

      --Datasheet P.1 ------------------------------------------------------------------------

      Note1. This device does not support automatic write-back on error detection.

      ----------------------------------------------------------------------------------------------

      We don't understand the meaning of the above.

      What does this Note 1. mean?

       

      Regards,

       

       

        • 1. Re: CY62148G30-45ZSXI ECC function
          PradiptaB_11

          Hi Masashi-san,

           

          This SRAM has embedded ECC on chip. The ECC mechanism will detect a single bit error if it is present and will automatically correct the error when a read is performed. So when you are reading say one of the bits is corrupted. The internal ECC will first read the bits detect one bit corruption correct it in the internal buffers and give the data out, but it will not write back the correct data in the memory location. The memory location still has corrupt data. On seeing the ERR pin asserted ( on those chips which have ERR pin) the user will understand that one bit error was detected and corrected for read and then he can write back the same data on to the memory location thereby correcting the error.

          You can read more about this in our app note on page 5, 6, 7.

          https://www.cypress.com/file/141291/download

           

          Thanks,

          Pradipta.

          • 2. Re: CY62148G30-45ZSXI ECC function
            MaMi_1205306

            Pradipta-san,

             

            Thank you for your support.

             

            This device (CY62148G30) has not ERR terminal.

            How do we determine if an error occurs?

             

            Regards,

            Masashi

            • 3. Re: CY62148G30-45ZSXI ECC function
              PradiptaB_11

              Hi Masashi-san,

               

              The device which does not have ERR pin, the user in that case cannot determine if an error has occurred. The errors will keep on accumulating and single bit error can turn into multi bit error but since the time taken will be very long as you can check in the SER reports that it will not affect any applications as SER rate for ECC devices is less than 0.1 FIT/Mb.

               

              Thanks,

              Pradipta.

              • 4. Re: CY62148G30-45ZSXI ECC function
                MaMi_1205306

                Pradipta-san,

                 

                Thank you for your response.

                 

                This device does not have an "ERR terminal" and "write back function".

                From the above two points,
                In applications that do not turn off the power for a long time,
                Although single bit errors are automatically corrected, errors in the cells themselves can not be improved.
                That's because it doesn't have a write back feature.

                Because this device does not have an ERR terminal,

                Even as an application, it is not corrected that an error has occurred because it is automatically corrected by ECC.


                After a long time, a multi-bit error occurs.
                I understand that SRAM can not correct data.

                 

                Regards,

                Masashi