Hi Lee,

I believe it is possible to configure BIST from the serializer (SER) side. You may want to follow these steps:

1. Establish the link between the SER and DES.
2. Access the DES through the SER-side I²C interface and place the DES in BIST mode.
3. Perform a soft reset on the DES.
4. Configure the SER to operate in BIST mode.
5. Perform a soft reset on the SER.

I hope this helps. Please let me know if it works.

Aaron

Hi Aaron,

Thank you for the quick reply, I’ve tried your suggestion and stalled at step 3

1. Establish the link between the SER and DES. O.K.
2. Access the DES through the SER-side I²C interface and place the DES in BIST mode. O.K. (Set DES ADD 0x24 to 0x01 for BIST On)
3. Perform a soft reset on the DES.
   1. Soft reset how, Set DES ADD 0x01 to 0x06 (Enable Digital RESET0) ? This does not work as there is no back-channel comms during BIST. I cannot read or write to the DES during BIST, I suspect this is because it’s being used for CRC errors ?

Please advise me further ?

Hi Lee,

Please let me know which DES are you using? I would like to try it on the bench.

Aaron

Hi Aaron, 

DS90UB928Q-Q1

Hi Lee,

Let me try it on my bench and I will get back with you.

Aaron

Hi Lee,

I performed the test per instruction below. I do not see any issue.

hex(board.ReadI2C(0x5a,0x0))
'0x5a'
hex(board.ReadI2C(0x5a,0x24))
'0x8'
board.WriteI2C(0x5a,0x24,0xb)
hex(board.ReadI2C(0x5a,0x24))
'0xb'
board.WriteI2C(0x5a,0x1,0x1)
hex(board.ReadI2C(0x5a,0x24))
'0xb'

Now you can set the BIST mode in serializer.

Aaron

Hi Arron,

I repeated your steps and commands, I also question some of your register settings, specifically : -

• board.WriteI2C(0x5a,0x24,0xb).
  • Bit 3 (1011) is set to 1 (Default) which sets BIST enabled from pin ? This will not set the Des in BIST. See my previous posts for how I have put the DES in BIST

• hex(board.ReadI2C(0x5a,0x24)). This read would not work if Bit 3 of DES 0x24 was set
• Now you can set the BIST mode in serializer. I have followed all your steps to this point. How can I do this ?
  • Bit 0 on Register 0x14 at the SER is ‘Read Only’
  • There is no way to read the BIST Error counter, BIST BC Error Count on the SER 0x1B does not appear to be the same counter.
    •  I have put the DES in BIST using my own method which then looses Back-channel, read the BIST BC Error Count (0x1B) which is zero, then shorted the FPD-Link and checked again, still zero.  

Is this possible to request support through an MS Teams call that way I can share my screen and we can work through this together ?

Hi Lee,

Have you configure the BIST mode on the serializer? This will enable full BIST mode. Yes you may schedule a time to discuss this. I am available on Friday if you are. Please let me know so that I can move the thread to private chat room.

Aaron

Hi Aaron, I would like for you to outline specifically how you can configure the SER for BIST using the registers ?

The registers I have seen 0x14 (BIST Control), Bit 0 is a Read Only. I think this is set from the Des Back channel.

Please can we schedule a time to discuss Friday. Please move to a private channel, we can update this is we are able to find a solution

Hi Lee,

I’ve just sent you a connection request—please accept it so we can coordinate and schedule a meeting.

In general, no additional configuration is required on the serializer side. Once enabled on the deserializer, it will automatically configure the relevant registers on the serializer. You can also monitor the PASS pin using an oscilloscope for verification.

Please let me know if you have any questions.

Aaron

O.K Great. Yes I know about the H/W pins regarding BIST i.e. PASS etc, but I do not have access to any of these as they were not routed out on the board; hence the reason why I need to do everything via the registers. This is where I'm running into problems

Hi Aaron, I have not seen the connection request, please advise where this is ? I will be in office specifically tomorrow (7:00 a.m - 12:30 p.m) to work on this issue  

Hi Aaron, Can you support me this morning ?

Hi Lee,

Please accept my friend request in your profile so we can continue our discussion in a private chat.

Alternatively, if you prefer, you may share your email address and we can coordinate communication that way.

I am based in Santa Clara, California. Could you please let me know your time zone so we can arrange a suitable time to connect?

Aaron

Hi Aaron, I've selected the 'Accept friend Request", but when I refresh the page it presents the same option appears so I'm not convinced this is working. I've tried using a different browser and same result.

I'm based in the UK so our time zones are 7Hrs ahead. I typically finish at 3:30 p.m. (GMT) so if we can arrange a suitable time before then Mon - Thurs it would be much appreciated. 

My e-mail is: - LeeAnthony.Smith@mt.com

Hi Lee,

I will send out the invitation shortly for tomorrow meeting 3/24.

Aaron