topic PCA9546A I2C MUX Bus Problem in Other NXP Products https://community.nxp.com/t5/Other-NXP-Products/PCA9546A-I2C-MUX-Bus-Problem/m-p/1041151#M8808 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P>I designed this into a new product or ours.</P><P></P><P>I notice that the chip frequently results in an I2C bus stuck event that needs recovery.</P><P></P><P>This occurs when writing the control register for a MUX selection, followed immediately bu a read to confirm the correct selection.</P><P></P><P>The bus will sometimes become stuck in that SDA remains low forever or until bus recovery procedure.</P><P>The bus become stuck at around bit 8 or Ack of read data address. See attached wave capture.</P><P></P><P>This happens at a frequency of around 1 in 1000 or in my case about every 3 minutes.</P><P></P><P>Bus operation is 100kHz.</P><P></P><P>What can cause this problem?</P><P></P><P>The bus signals are clear and beautiful. Is there a minimum time specification between a write followed by read ?</P><P>I cannot see it in the datasheet.</P><P></P><P>Regards</P><P>Bernt</P></BODY></HTML> Wed, 29 Jul 2020 22:33:13 GMT berntau 2020-07-29T22:33:13Z PCA9546A I2C MUX Bus Problem https://community.nxp.com/t5/Other-NXP-Products/PCA9546A-I2C-MUX-Bus-Problem/m-p/1041151#M8808 <HTML><HEAD></HEAD><BODY><P>Hi,</P><P>I designed this into a new product or ours.</P><P></P><P>I notice that the chip frequently results in an I2C bus stuck event that needs recovery.</P><P></P><P>This occurs when writing the control register for a MUX selection, followed immediately bu a read to confirm the correct selection.</P><P></P><P>The bus will sometimes become stuck in that SDA remains low forever or until bus recovery procedure.</P><P>The bus become stuck at around bit 8 or Ack of read data address. See attached wave capture.</P><P></P><P>This happens at a frequency of around 1 in 1000 or in my case about every 3 minutes.</P><P></P><P>Bus operation is 100kHz.</P><P></P><P>What can cause this problem?</P><P></P><P>The bus signals are clear and beautiful. Is there a minimum time specification between a write followed by read ?</P><P>I cannot see it in the datasheet.</P><P></P><P>Regards</P><P>Bernt</P></BODY></HTML> Wed, 29 Jul 2020 22:33:13 GMT https://community.nxp.com/t5/Other-NXP-Products/PCA9546A-I2C-MUX-Bus-Problem/m-p/1041151#M8808 berntau 2020-07-29T22:33:13Z