HD3SS213: AUX/DDC Switch Control Logic

you may right, let's check with system guy

Hi David-san, Brian-san,

Thank you for your quick reply.

I will wait for your check result.

Best regards,
Fumio Nakano

Fumio-san

I confirmed that the table is correct, the description is a typo and needs to be updated.

Thanks
David

Hi David-san,

Thank you for your check.

But, sorry my correction was wrong.

My customer pointed out my correction error.

Please read below.

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Thank you for your response.

But according to your correction, the Dx_SEL signal will have 3 configurations: L, H and M,

while AUX_SEL only has 2 configurations: L and H. That conflicts with the rest of the datasheets

and the schematic is shown below (HD3SS213 EVM):

image.png

:

Please check it again and let me know as soon as possible.

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I think that the table should be corrected as follows.
Please check it again.

 

Best regards,
Fumio Nakano

Hi David,

How about the Table 1. HD3SS213 EVM Jumper Description and Settings (in the HD3SS213 EVM)? Does it also need to be updated?

Thanks,
Hai

Hai

AUXSEL jumper definition needs to be expanded for more detail in the EVM user guide. But please refer to table 1 of the HD3SS213 datasheet for the correct mapping of switch control logic.

Thanks
David

Hi David,

Thank you very much for your support.

I have another question about pull-up resistors for DDC signal.

Let see the schematic below:

I have read the datasheet of TDMS181 and HD3SS215 for the HDMI application,

but I have a problem about the value of pull up resistors for DDC clock and data.

Could you tell the value of R1 to R10?

Thanks and best regards,

Hai

Hai

Same question has been addressed in this e2e thread: e2e.ti.com/.../737162.

Thanks
David

Hi David,

Thank you so much for your support.

Sorry to bother you, but I have another question.

I wonder if the HD3SS214 can be used to switch from one of two sources to one sink and one source to one of two sinks

in one application by using some control pins, as shown below:

Fig.1. Control pins for HD3SS214 switching

For switching from one of two sources to one sink, the configuration as shown in Fig 2.

Fig.2. 2:1 Application for HD3SS214

And for switching from one source to one of two sinks, see Fig 3.

Fig.3. 1:2 Application for HD3SS214

Can I do that? 

Thanks and best regards,
Hai

Hi David,

Thank you for pointing out my problem.

Then I modified the configuration. Let's see two figures below:

 

 

Based on this configuration, the displayport switcher does not change to serve two different purposes.

I think it just the name of the Lanes are replaced (ex: Lane 0 instead of Lane 3, Lane 1 instead of Lane 2, ...),

but the trace will not change. It only needs the crossover trace between the HD3SS214 and the Connector C.

Is it right?

Thanks & Best Regards,

Hai

Hai

You need to make sure the lane ordering is correct when going from the source to the sink.

Thanks
David

Hi David,

I follow this image for lane ordering. I make the DP switcher look like a cable.

Then the source will connect to the sink through 3 cables (source => cable 1 => switcher (Cable 2) => cable 3 => Sink)

It is the same as connecting through 1 cable. Thus, the order of lane will not change.

Beyond the lane ordering, is there any other problem when using the HD3SS214 to serve two different purposes?

Thanks and best regards,

Hai

Hai

HD3SS214 supports 2:1 and 1:2 DP differential switch. Because it is a switch, it does not have any equalizer or re-driving capability, please make sure the sink can support the total loss of 2 cables plus HD3SS214.

Thanks
David

Hi David,

Thank you for reminding me. I will carefully consider this issue.

Thanks and best regards,

Hai