5 Replies Latest reply on Mar 18, 2019 12:16 AM by ShYa_3490236

    Can CY7C65211 communicate with CY15B104Q via SPI?

    ShYa_3490236

      Hi,

       

      We plan to use CY7C65211 as SPI master, and CY15B104Q (FRAM) as slave.

      Regarding the description of CY7C65211 and CY15B104Q datasheet;

       

      - CY7C65211 SPI master spec : Thmo (hold time) is 0ns min.

      - CY15B104Q SPI slave spec : tH (Data hold time) is 5ns min. (VDD=2.7 to 3.6V)

           * Both of configuration are CPOL=0 (Mode0)

       

      Is communication specs out of range in this configuration?

      In the CY7C65211 output the SCK and Valid data to slave with no hold time, but CY15B104Q can not latch correctly due to hold time is insufficient.

      I’m afraid that valid data sent by host but can not be received correctly by slave.

      Is my understanding correct?

       

      Best regards, Shohei

        • 1. Re: Can CY7C65211 communicate with CY15B104Q via SPI?
          SananyaM_56

          Hello Shohei-san,

           

          -Kindly change the modes in the USB Serial to CPHA=1, CPOL=0 (mode 1), CPHA=0, CPOL=1 (mode 2) and check if the write still fails.

          -Please ensure that the SPI write enable commands and address sent are as per the slave requirements.

          If possible please capture the waveforms using a logic analyzer showing the state of the SPI lines during the transfers.

           

          Best Regards,

          Sananya

          • 2. Re: Can CY7C65211 communicate with CY15B104Q via SPI?
            ShYa_3490236

            Hi Sananya-san,

             

            Thank you for your reply.

            I'm planning to evaluate this combination (CY7C65211 w/CY15B104Q) but now in the conceptual phase. 

            So, based on both of datasheet specs, let me know your opinion whether I can use this FRAM product.

            If I can use, i plan to prepare the CY15B104Q samples and configure the environment for evaluation.

             

            I think that this FRAM can not be used due to hold time spec is not meet.

            I just want to make sure the above my understanding.

             

            Best regards, Shohei

            • 3. Re: Can CY7C65211 communicate with CY15B104Q via SPI?
              ShYa_3490236

              Hi Sananya-san,

               

              Do you have any update?

              As a result of re-confirming datasheet specs, I think that hold time spec (0ns min.) is not the master side spec, it is the slave side spec.

              In other words, if the hold time of slave side is 0ns or more, it can be OK. Hence CY15B104Q can be used.

              Let me know your kindly advice.

               

              Best regards, Shohei

              hold time = 0ns(min)というのはマスタの出力仕様ではなく、スレーブの持つべき性能要求ではないですか?

              つまり、スレーブ側がhold time = 0ns以上であればOKという意味合いにも取れます。

              • 4. Re: Can CY7C65211 communicate with CY15B104Q via SPI?
                SananyaM_56

                Hi Shohei-san,

                 

                Yes your understanding in the last response is correct. The datasheet for USB-Serial device is mentioning hold time requirement with respect to the slave device and hence can support SPI slave with hold time of 0ns or higher since hold time is considered for the data sampling.

                Hence the CY15B104Q can be used.

                I will however also test on my end and update.

                 

                Best Regards,

                Sananya

                • 5. Re: Can CY7C65211 communicate with CY15B104Q via SPI?
                  ShYa_3490236

                  Hi Sananya-san,

                   

                  Thanks for the response. Got it. Let you know when I have further question.

                   

                  Best regards,

                  Shohei