DS90UB954-Q1EVM: I2C Addressing two Serializers DS90UB953 connected to one Deserializer

Shai Ludvinovsky

Prodigy 50 points

Part Number: DS90UB954-Q1EVM
Other Parts Discussed in Thread: DS90UB953-Q1

Hello TI community,

I want to make a set up containing the following (see drawing below):

- One Deserializer EVB DS90UB954

- Two custom boards that contain DS90UB953-Q1 device

- Two camera modules, each connected to one Serializer with MIPI connector

I wish to know:

1. Is it obligatory to configure (using pullup resistors) a different I2C address for each Serializer board? Or can I leave both of them with address 0x18(7b) with pulldown resistors on their IDX pin?

2. Same question for my CMOS sensors - is it obligatory to set each CMOS a different I2C address using pullup resistor? Or does the Deserializer distinguish between the sensors by the selected RX port?

3. I'm trying to figure out how to send I2C commands to each Serializer and sensor in this setup. I read in the datasheet that register address 0x4C of the Deserializer selects the RX ports. But what if I want to write to two Serializers simultaneously? If I write '0x03' to 0x4C register (for example) how does the Deserializer know which sensor is it writing to? Could you please suggest me what to write to registers SerAlias, SlaveID[0], SlaveID[1], SlaveAlias[0], SlaveAlias[1] of the Deserializer with this configuration?

Thank you!

Shai

over 4 years ago

0 Casey McCrea over 4 years ago

TI__Guru* 98505 points

Hello Shai,

Please see the 954 datasheet section 7.5.4 which describes this situation and how to address it. You can also reference this app note which is for older devices but uses similar concepts: http://www.ti.com/lit/an/snla222/snla222.pdf

Best Regards,

Casey

0 Shai Ludvinovsky over 4 years ago in reply to Casey McCrea

Prodigy 50 points

Hello Casey,

Thanks for the references, I read them but there's one thing that wasn't fully explained there.

The Deserializer registers table contains only one register that holds SER-ID and only one register that holds SER-ALIAS.

If I connect one Serializer to port 0 and another Serializer to port 1, which address is auto-written to SER-ID register? if I don't reprogram and both Serializers' address is 0x18, how can I know which Serializer was selected by the Deserializer?

Thank you,

Shai

0 Shai Ludvinovsky over 4 years ago in reply to Shai Ludvinovsky

Prodigy 50 points

Nevermind, I just saw myself in Analog Launchpad GUI that when I select a specific RX port and write a special Alias for each Serializer, the Deserializer remembers which Alias belongs to each port.

Thank you!

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DS90UB954-Q1EVM: I2C Addressing two Serializers DS90UB953 connected to one Deserializer