TMDS181: TX_TERM_CTL behaviour

Martin Seeger

Part Number: TMDS181

Dear Team,

we received a question regarding the TX_TERM_CTL behaviour in a situation with non-connected TX_TERM_CTL pin:

Suppose these are our pin-strap values:

SWAP/ POL - M (floating)
I2C_EN/PIN – H
SIG_EN – L
PreSel – M (floating)
EQSelA0 – H
TestA1 – H
TXTermCtl – M (floating)

So we put the device in I2C Control Mode. Then it is not really clear to us how the device will behave.

According to pinstrap description, we will get the automatic mode :

But according to I2C register description, we will have NO termination :

Any help is very much appreciated.

Best Regards
Martin

over 8 years ago

0 Moises Garcia over 8 years ago

TI__Mastermind 23815 points

Hi Martin,

When I2C_EN=High, Tx termination is controlled by I2C, by default it has no termination and state of TX_TERM_CTL pin is ignored.

When I2C_EN=Low, Tx termination is controlled by TX_TERM_CTL pin, The state of Tx termination is readable in TX_TERM_CTL register. This is why the register has RWU, the U means it updates from control pin.

Regards

0 Martin Seeger over 8 years ago in reply to Moises Garcia

TI__Expert 5411 points

Hello Moises,

thank you very much for the reply.
This answered the customer's question!

Best Regards (&Happy New Year)
Martin

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TMDS181: TX_TERM_CTL behaviour