DS90UH926Q-Q1: Working without a serializer

Thank you very much Ikram.

I need to view a "No signal" image to the display if the serializer is not connected to the deserializer. I think to connect RGB signals both to the MCU and the deserializer: when the deserializer is working the MCU puts its RGB signals in high impedance and viceversa. 

Are there other solutions?

Thank you

Hi Matteo, 

On the 926 (DES), the LOCK pin indicates Link Status. So the MCU can check the LOCK pin to detect whether SER is connected or there is "No signal" condition"

After detecting this, can the MCU or other device (TCON, display, etc) on the display side output the "No signal" image? 

Best regards,
Ikram

Hi Ikram,

we are currently searching for the best solution to show the "no signal" image to the display. Is the MCU the only possibility to show such image or are there other ICs?

Best regards,

Matteo

Hi Matteo,

The 926 deserializer can output a Test Pattern, like those mentioned in this App Note. These are built-in color patterns listed in the "2.4 Pattern Selection" section. So they are not specific images with "no signal" or other text.  

They can monitor the LOCK pin on the DES, and after LOCK is lost, the MCU can write via I2C to the DES to enable this. Let me know if this works for your application. 

Best regards,
Ikram

Hi Ikram,

thank you for your feedback. Unfortunately, this will not work for our application because the customer wants the "no signal" image.

Is it ok to place a MCU with RGB interface in parallel to the RGB interface of the deserializer?

Best regards,

Matteo

Hi Matteo,

On the datasheet there's examples of "Repeater" applications where the RGB interface fans out to multiple receivers. I'll have to check whether the MCU's parallel input can be used here. Please give me till Tuesday to ask the team and get back to you.



Best regards,
Ikram

Thank you Ikram, really appreciate your effort.

I'm really sorry but I don't understand why you suggest to use this configuration. Just to be clear I'd like to tell you the scenario.

1. In normal operation the remote serializer transmit video data to the local deserializer.

2. If the remote serializer goes down for some reason, the local display must show a "No signal" image.

3. To do so, we suppose that we need an MCU to drive the display when the serializer is down. But we are currently searching for other solutions other than the MCU (if they exist, obviously)

Thank you,

Matteo

Hi Matteo,

Oh, sorry I didn't clarify fully. I wasn't suggesting that configuration, I was just referring to it to say that output to multiple RX is possible from the 926. Meaning the 926 can output parallel RGB.

However, for your case, I understand that you want multiple alternate RGB inputs (one from 926 and one from MCU) to the display. I don't know of an MCU that can produce RGB output of an image though.

I'll check with the team if we have any similar system solutions.

- Ikram

Hi Matteo, since I focus on the Ser-Des devices only, I would suggest to consult about this with a TI field applications engineer, if you have a contact. They might be able to suggest a suitable solution for this. 

Best regards,
Ikram