3 Replies Latest reply on Feb 14, 2019 10:30 AM by BushraH_91

    Can I read data when data is written with ECC invalid?

    NaMo_1534561

      Hello,

       

      NOR Flash with automatic ECC function will generate valid ECC code when issuing the Write Buffer Programming command.

      On the other hand, when executing the Single Word Programming command or overwriting data on the same page, the ECC code is invalid.

       

      At this time, if data is read, can the data be read while ECC is invalid?

      Or is the data itself read invalid?

       

      MPN S29GL01GT10TFI010

       

      Best Regards,

      Naoaki Morimoto

        • 1. Re: Can I read data when data is written with ECC invalid?
          BushraH_91

          Hello,

          Thank you for contacting Cypress Community Forum.

           

          Yes, the data is still valid and readable while ECC is disabled by single word programming or overwriting data on the same page.

           

          The ECC code in NOR is not accessible (read/write) from outside. It is used by NOR device to provide maximum data reliability, i.e., if there is a bit error generated in a page, NOR device can still output correct data with valid ECC.

           

          It is strongly recommended that application uses write buffer programming to write NOR flash whenever it is possible, to achieve maximum data reliability and better write performance.

           

          If application has to write multiple times in the same page within a erase cycle, try to minimize the write times, less times better data reliability.

           

          Have a nice day

          Regards,

          Bushra

          • 2. Re: Can I read data when data is written with ECC invalid?
            NaMo_1534561

            Hello Bushra-san,

             

            Thank you for your answer.

            If ECC is invalid, will the read data be read by bypassing the ECC circuit?

            Also, can I check the status with the ECC status ASO register when ECC is invalid by writing with the single word programming command or overwriting on the same page?

             

            Best Regards,

            Naoaki Morimoto

            • 3. Re: Can I read data when data is written with ECC invalid?
              BushraH_91

              Hello,

              If ECC is invalid, will the read data be read by bypassing the ECC circuit?

              Answer: Yes. If ECC is disabled, when reading data from that page, the flash will output the array data as is, will not do ECC check and correction.

              Also, can I check the status with the ECC status ASO register when ECC is invalid by writing with the single word programming command or overwriting on the same page?

              Answer: Yes, at flash read mode, system can access ECC Status ASO by issuing the ECC Status entry command sequence. The ECC Status Word tells the ECC status (see attached doc). ASO Exit command is required to exit from ECC Status ASO and bring flash back to read mode.

               

               

              Have a nice day

              Regards,

              Bushra