DS90UB949-Q1: Screen Displays Vertical Lines (2)

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Part Number: DS90UB949-Q1


I'm back in the office now so I have access to my setup. I don't have access to the I2C bus on the deserializer side since it's part of the customer module, so in order to run the BIST I substituded the DS90UB948 EVM and Analog Launchpad software. The procedure was as follows:

1. In ALP, set Deserializer register 0x24 to 0x01 (Enable BIST)
2. The orange LED on the EVM (connected to the PASS pin) lights up
3. After BIST has run for several seconds, set Deserializer register 0x24 to 0x00 (Disable BIST)
4. The orange LED turns off, indicating that at least one error occurred during BIST
5. Read Deserializer register 0x25 (BIST Error Count). Register value is zero, which contradicts the low PASS pin.
6. In ALP Remote Registers tab, read Serializer register 0x1B. Register value is 0x04.

I'm not really sure how to interpret this data. The BIST Error Count register is zero, so does that mean the FPD-Link III signal integrity is ok? Why is the PASS pin going low after the BIST if there were no errors? Is this due to the back channel errors? I'd appreciate some guidance from TI.


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