DS90UB948-Q1: work abnormal

Hi Jeff, 

I have sent you a friend request for private message. Please accept and send more details regarding the issue. 

Things that would help me:

Pairing serializer, mode settings/hardware strap modes, power up sequence etc...

Best,

Shu

Hi Shu,

I have send debug report to you by privacy message, please help check and get us suggestion. thanks!

Jeff

Hi Shu,

And for DS90UB948-Q1 test, doesTI have any demo board can send FPD link signal?

it for manufacture verify function needed.

If yes, please tell us how to setting this demo board.

Thanks!

Jeff

Hi Jeff, 

I am taking a look over the report and will get back to you in 1-2 business days. 

Best,

Shu

Hi Shu,

Got it, please let us know if any update.

As previous discuss, about DS90UB948-Q1 test, does TI have any demo board can send FPD link signal?

it for manufacture verify function needed.

If yes, please tell us how to setting this demo board.

Thanks!

Jeff

Hi Shu,

We are follow 7.3.7 Serial Link Fault Detect to check what is wrong,

But confuse about item 5 and 6, what is the battery means? VDD? thanks!

Jeff

Hi Jeff, 

We have evaluation boards for our partnering serializers such as the 941 (DSI interface), 947(OLDI Interface) and 949 (HDMI interface) that can send FPD-Link signal to the 948. This is what you are asking about? 

Regarding the line fault question, battery implies VDD. 

Best,

Shu

Hi Shu,

Yes, that we asking about, seems we can use 947 EVM send FPD link signal to 948 for the test.

And how about the can't connect issue, what is your opinion?

Thanks!

Jeff

Hi Jeff, 

Based on the provided report, it is hard to tell where the link issue is coming from. Are you having issues between the 948 and the display or is it the 947 connecting to the 948? 

I suggest using the 947 EVM to test the 948+display and perform image bring up. That way we can narrow down the issue as it is unclear which hardware is the root cause. There is a build in pattern generator function on the 94x devices, I am attaching an app note to help along with the 947 EVM Users Guide. 

Pattern Generator App Note:

5125.snla132g_PatGenFPD3.pdf

947 EVM Users Guide: https://www.ti.com/lit/ug/snlu140a/snlu140a.pdf?ts=1666626992930&ref_url=https%253A%252F%252Fwww.google.com%252F

Best,

Shu

Hi Shu,

Got it, we have ask customer buy 947EVM to clarify this issue.

And customer ask in the same time, is it possible to send their 948 board to you to check this issue?

Thanks!

Jeff

Hi Jeff, 

We recommend the customer try the 947 EVM first as they know their system best. If that is still unable to help deduce the issues, we can discuss further steps that may involve sending the system to TI. 

Best,

Shu

Hi Shu,

We measure pin 48 PDB only 1.9V, seems it may caused IC work abnormal, but we follow the EVM reference design, only pull high this pin to 3.3V as below.

Do you have any idea about this?

Thanks!

Jeff

Hi Jeff, 

I will need to look more into this, I will get back to you on 11/1. 

Best,

Shu

Hi Jeff, 

Per the 947 datasheet, with a 3.3V VDDIO, a high level voltage is >2.1V and low level voltage is <1.15V. The measured 1.9V PDB is considered unknown state and would prevent the IC from functioning properly and locking. Is the above schematic you shared the customer board? 

Best,

Shu