DS90UH929-Q1: Response speed of HPD pin

Nao

Part Number: DS90UH929-Q1

Hi, E2E members

I would like to know the response speed of HPD pin.
DS90UH929 datasheet says that the HPD pin is asserted by the sink( I guess it is 929.) to
let the source know that it is ready to receive the HDMI signal.

How long does it take the HPD pin is asserted by the 929 after providing the +5V power
signal through the HDMI interface?

Regards,
Nao

over 6 years ago

0 Palaniappan Manickam over 6 years ago

TI__Genius 10475 points

Nao,

The HPD should be pulled high once the 929 (sink) is ready to receive the HDMI signal from the source (processor) if everything is connected correctly and the 5V becomes available from the source.

0 Nao over 6 years ago in reply to Palaniappan Manickam

Genius 4905 points

Hi, Palaniappan

Thank you for your feedback.
I understand that you say.
Please tell me the absolute time.

Regards,
Nao

0 Darryl Jeong over 6 years ago

TI__Expert 4210 points

There is not a fixed delay as the 929 and DES go though a state machine to determine when HPD is determined. I will see if we have any characterization data for a maximum value.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your feedback.
Do you have a state machine of state transition diagram?

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,
Sorry for the delay. I have to go the the design archive to find the state machine transition diagram but I have not found it yet.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

I'm sorry to rush you, but our customer is waiting for this answer.
Can you find it? Do you have any update?

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,
I can only share this part of the state machine as it is integrated with the HDCP logic:
Part of the state machine includes the following operations:
• Main control loop (through IDLE state) when rx5v_detect is asserted
• Clear HPD – When rx5v_detect is false, or on a downstream HPD event, clear HPD and also reset audio FIFO in the HDMI controller
• Set HPD – On each cycle through the state machine, set HPD. This is to ensure this gets reasserted in case it was deasserted by an external controller
• Get RX Status – Gets Status from the HDMI controller by calling the RX Status state machine

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your feedback.
Can I get your answer about my original question?

======
How long does it take the HPD pin is asserted by the 929 after providing the +5V power signal through the HDMI interface?

or

Can I get max time for it?
======

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,
I can measure a typical value which you can guardband.
I have to modify an EVM to take the measurements next week.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your reply.
I'm waiting for your measurements data.

Regards,
Nao

0 Nao over 6 years ago in reply to Nao

Genius 4905 points

Hi, Darryl

I will appreciate your cooperation.
Can I get your feedback in this week?
I need to send this feedback and schedule to our customer.
Please send your plan.

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,
My appologies for the delay. I have been out of the office and won't be back until Thursday, Nov 8th.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your reply.
I'm waiting for your update.

Regards,
Nao

0 Nao over 6 years ago in reply to Nao

Genius 4905 points

Hi, Darryl

Can I get your feedback in this week?

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao-san,
I have been out of the office. One of my co-workers is helping me take the measurement. We should have the measurement by the end of the week.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your feedback.
I will ask our customer to wait the answer until this end of week.

Regards,
Nao

0 Nao over 6 years ago in reply to Nao

Genius 4905 points

Hi, Darryl

Do you have any update?

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,
We tried to take the measurement on Friday, but ran into EVM not working so we are currently debugging the setup. I will need another day or so.

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your reply.
Let me know soon, if you get it.
Our customer is waiting for our reply.

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,

I have HPD bench testing results.
Thank you for your patience.

Setup:
DS90Ux929EVM->DS90Ux948EVM
FPD3 cable interface connection between EVMs length 1 meter
FPD3 cable Leoni/dacar 535-2 cable with Rosenberger HSD connector
VDDs = nominal
HDMI source = laptop
Hot plug HDMI cable into DS90Ux929EVM
Trigger on Rx_5V (50% on rising edge )
monitor HPD (50% on rising edge )

Sample size = 10 mechanical hot plugging of HDMI cable into DS90Ux929EVM
Results:
avg = 357.56ns,
min = 339.5ns,
max = 371.2ns

Measurement data collected using CH1 to CH2 delay in time tab:

1 367.6ns
2 348ns
3 371.2ns
4 354.1ns
5 361ns
6 365.6ns
7 355.3ns
8 357.9ns
9 339.5ns
10 355.4ns

Misc:
Scope TEK TDS 6604 6GHz 20GS/s x1
Probes TEK P6247 1GHz differential probe x2
DC Power supply hp6023A 0-20V/0-30A, 200W

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darrly

Thank you for your update.

Regards,
Nao

0 Darryl Jeong over 6 years ago in reply to Nao

TI__Expert 4210 points

Hi Nao,

I sent this out yesterday but did not see it post for some reason. Here it is again.

I have HPD bench testing results.
Thank you for your patience.

Setup:
DS90Ux929EVM->DS90Ux948EVM
FPD3 cable interface connection between EVMs length 1 meter
FPD3 cable Leoni/dacar 535-2 cable with Rosenberger HSD connector
VDDs = nominal
HDMI source = laptop
Hot plug HDMI cable into DS90Ux929EVM
Trigger on Rx_5V (50% on rising edge )
monitor HPD (50% on rising edge )
Termperature = room

Sample size = 10 mechanical hot plugging of HDMI cable into DS90Ux929EVM
Results:
avg = 357.56ns,
min = 339.5ns,
max = 371.2ns

Measurement data collected using CH1 to CH2 delay in time tab:

1 367.6ns
2 348ns
3 371.2ns
4 354.1ns
5 361ns
6 365.6ns
7 355.3ns
8 357.9ns
9 339.5ns
10 355.4ns

Misc:
Scope TEK TDS 6604 6GHz 20GS/s x1
Probes TEK P6247 1GHz differential probe x2
DC Power supply hp6023A 0-20V/0-30A, 200W

0 Nao over 6 years ago in reply to Darryl Jeong

Genius 4905 points

Hi, Darryl

Thank you for your feedback.
I will tell our customer the measurement data.

Regards,
Nao

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DS90UH929-Q1: Response speed of HPD pin