TMDS181: polarity inversion of input and output

Daniel Baldor

Part Number: TMDS181

In order to have a clean layout I would like to swap both the input and output polarity of the hdmi signals going in and out of the TMDS181. Would this work or will it cause a problem?

Thanks

over 7 years ago

0 Michael.Walker over 7 years ago

TI__Mastermind 19720 points

Polarity doesn't matter for redriver mode, but it does matters for retimer mode.

0 Daniel Baldor over 7 years ago in reply to Michael.Walker

Intellectual 340 points

For retimer mode would it be necessary to set the lane_polarity bit (bit 6 of address 0x9)? If so can I set both the lane_swap and and lane_polarity at the same time? Would there be any downside to keeping the device in retimer mode the whole time? We are using the chip to receive HDMI data into an FPGA and it would be easier if we can keep the polarity consistent across all data rates.

0 Michael.Walker over 7 years ago in reply to Daniel Baldor

TI__Mastermind 19720 points

Yes you can swap the polarity in retimer mode with that register. Yes you can do both lane_swap and lane_polarity at the same time. the only drawback would be power consumption which is listed in the datasheet. you can keep the polarity the same across data rates.

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TMDS181: polarity inversion of input and output