4 Replies Latest reply on Jul 18, 2018 11:38 PM by srnt

    About I2C bit rate

    arai-n_1540581

      Hello

       

      We are understanding that the operating frequencies supported are 400 kHz and 1 MHz when VIO5 is 1.8 V, but the customer said that they want to use I2C bit rate as 100kHz when VIO5 is 1.8V.

      Is it possible or not?

       

      Best regards

      Arai

        • 1. Re: About I2C bit rate
          srnt

          Hello Arai-san,

           

          I believe you are talking about the FX3 device.

          FX3 supports maximum I2C frequency of 100kHz when VIO5 is 1.2V. If VIO5 is 1.8V, FX3 I2C supports I2C frequencies of 100kHz, 400kHz and 1MHz.

           

          Best regards,

          Srinath S

          • 2. Re: About I2C bit rate
            arai-n_1540581

            Hello Srinath san

             

            FX3 datasheet is described below.

             

            >The I2C controller supports bus frequencies of 100 kHz, 400 kHz, and 1 MHz. When VIO5 is 1.2 V, the maximum

            >operating frequency supported is 100 kHz.   """ When VIO5 is 1.8 V,2.5 V, or 3.3 V, the operating frequencies supported are 400 kHz

            >and 1 MHz.""""

             

            I am understanding that If VIO5 is 1.8V, FX3 I2C supports I2C frequencies of 400kHz and 1MHz, and 100KHz is not including. Is it correct? If correct, is there any method using 100kHz when VIO5 is 1.8V.

             

             

            Best Regards

            Arai

            • 3. Re: About I2C bit rate
              arai-n_1540581

              Hello

               

              Any updates? We have to fix this problem ASAP.

               

              Best Regards,

              Arai

              • 4. Re: About I2C bit rate
                srnt

                Hello Arai-san,

                 

                When VIO5 is 1.8V, FX3 I2C supports all three frequencies. This can be tested using the FX3 DVK. The firmware image file can be generated for I2C frequency of 100kHz and the VIO5 can be set to 1.8V. The I2C boot of FX3 has been found to be successful indicating that I2C at 100kHz works at VIO5 as 1.8V.

                 

                Best regards,

                Srinath S