DS90UB936-Q1: Back channel GPIO mapping support

Part Number: DS90UB936-Q1


It seems that mapping GPIO from Deserializer to Serializer is not support.

I found below post, the answer didn't solve the question: map 936 GPIO5 to 935 GPIO3.

The register 0x6E - 0x6F (BC_GPIO_CTL) is just set serializer GPIO value, not map 936 GPIO5 to 935 GPIO3.


Can anyone clarify this question?


  • Hello Chris,

    yes this is supported!

    Are you also looking for how to forward GPIO5 to GPIO3, or you do have different GPIOs?

  • Hi

    Thanks for your quick reply.

    I do have different setting. I need map Deserializer GPIO0,1,2, from rxport1 Serializer GPIO0,1,2

    Deserializer GPIO3 as interrupt

    Deserializer GPIO4 to rxport1 Serializer GPIO3

    Deserializer GPIO5,6 to rxport0 Serializer GPIO0,1,0

    Please check following table, could you give how to set the register setting?

                    Deserializer          Serializer        Note      
    SOC I2S   <-    GPIO0           <-    rxport 1, GPIO0   Microphone, FRCK
    SOC I2S   <-    GPIO1           <-    rxport 1, GPIO1   Microphone, BCK
    SOC I2S   <-    GPIO2           <-    rxport 1, GPIO2   Microphone, SDATA
    SOC GPIO  <-    GPIO3(INT)
    SOC GPIO  ->    GPIO4           ->    rxport 1, GPIO3   Camera power
    SOC GPIO  ->    GPIO5           ->    rxport 0, GPIO1   Camera power
    SOC GPIO  ->    GPIO6           ->    rxport 0, GPIO0   Camera reset

  • Hello Chris,

    so you want the following settings, correct?

    936 RX Port0:
    Input = GPIO5 to SER GPIO1
    Input = GPIO6 to SER GPIO0

    936 RX Port1:
    Input = GPIO4 to SER GPIO3

    Output = GPIO0 from SER GPIO0
    Output = GPIO1 from SER GPIO1
    Output = GPIO2 from SER GPIO2
    Output = GPIO3 Interrupt

  • Hi ,

    Yes, that's exactly correct.

  • Chris,

    your settings should look like following:

    0x0F = 0x70
    0x10 = 0x05
    0x11 = 0x25
    0x12 = 0x45
    0x14 = 0x00
    0x15 = 0x00
    0x16 = 0x00
    0x4C = 0x01
    0x6E = 0x56
    0x4C = 0x12
    0x6F = 0x40

    RX Port0 935:
    0x0D = 0x30
    0x0E = 0x30

    RX Port1 935:
    0x0D = 0x80
    0x0E = 0x87
    Output=GPIO3 Interrupt --- Please refer to section "7.5.8 Interrupt Support" in the datasheet.