TPS65313-Q1: LBIST is only partially working

Florian Wank

Prodigy 200 points

Part Number: TPS65313-Q1

Tool/software:

Hi,

we are currently having issues with the LBIST of the TPS65313-Q1.

What is working:

(0) setting the LBIST_EN in SAFETY_LBIST_CTRL seems to trigger the LBIST, because the Bit LBIST_DONE in SAFETY_LBIST_ERR_STAT gets set

What is not working:

(1) setting LBIST_EN cannot be verified by reading back LBIST_EN - the register reads back as 0 (direct readback after write, so delay of 5-20 microseconds) (The datasheet states that "bit is self-cleared when the LBIST run is completed")

(2) setting any other bit in SAFETY_LBIST_CTRL cannot be verified by reading back - the register reads back as 0 (direct readback after write, so delay of 5-20 microseconds) (The datasheet states that all these bits are "self-cleared when the LBIST run is completed")

(3) as stated in the datasheet the bit LBIST_DIAG_EN should not be set at same time as LBIST_EN - so only set LBIST_DIAG_EN, but SAFETY_LBIST_ERR_STAT bit LBIST_DONE stays at 0 forever (LBIST_DIAG_EN bit description says "The self-test status is monitored through bits D0 and D2 in the SAFETY_LBIST_ERR_STAT register." - where D0 is LBIST_DONE, what gets not set) - are there additional steps to get the LBIST_DIAG_EN run, or is it just setting this bit?

Thanks for your support

Florian

10 months ago

0 Niko Alatalo 10 months ago

TI__Mastermind 18740 points

Hi Florian,

(1) There is no read-back bit for running LBIST so this is working correctly but apparently missing a feature you would need. The LBIST or ABIST enable bits are not latching at all and since can't be used for read-back at all.

(2) Same as (1)

(3) I was able to replicate this on the EVM as well and have asked about this from the team. I will get back to you once I hear back from them but they had out of office messages so it could take until next week for me to get a reply from them.

regards,

Niko

0 Florian Wank 10 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

thanks for your quick reply.

I look forward to hearing from you soon according (3)

Best regards,

Florian

0 Florian Wank 9 months ago in reply to Florian Wank

Prodigy 200 points

Hi Niko,

is there an update for this issue?

Best regards,

Florian

0 Niko Alatalo 9 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

I am still checking this with the team.

regards,

Niko

0 Florian Wank 9 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

did you receive an update from the team?

Best regards,

Florian

0 Niko Alatalo 9 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

I have been discussing with the team but unfortunately I have not been at the office this week so I have not been able to test this on the EVM. If I get to the office this week I will test some things on the EVM and get back to you.

regards,

Niko

0 Florian Wank 9 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

do you have any updates about this issue?

regards,

Florian

0 Niko Alatalo 9 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

I have received further information from the team but have not been able to test this in the lab. I will try to test this and provide you feedback by end of this week.

regards,

Niko

+1 Niko Alatalo 8 months ago in reply to Niko Alatalo

TI__Mastermind 18740 points

Hi Florian,

sorry for the delay. I have now tested this in the lab and it seems there might be a mistake in the data sheet. To run the LBIST in diagnostic mode you first have to set the LBIST_DIAG_EN and then run LBIST_EN. Now the LBIST will run in diagnostic mode. It seems like the device only sets the LBIST_DONE bit after completion but I am still waiting for confirmation on this from the team.

The full sequence to run LBIST diagnostics in DIAGNOSTIC or ACTIVE state is:

1. Open the CTRL_LBIST_LOCK

2. Set LBIST_DIAG_EN

3. Set LBIST_EN

4. After the completion of the diagnostic run the device will set LBIST_EN bit to 1.

regards,

Niko

0 Florian Wank 8 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

thanks for your support. We will prepare this sequence and if you have the confirmation we will start testing.

regards,

Florian

0 Niko Alatalo 8 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

ok great I will let you know when I get the confirmation.

regards,

Niko

0 Florian Wank 8 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

during implementation some important questions came up:

[1] Regarding Step 4 : did you mean LBIST_DONE flag in SAFETY_LBIST_ERR_STAT?

[2] Are there any timing requirements for the sequence?

Example 1:

(Step 1) Open CTRL_LBIST_LOCK

Delay of just a few us

(Step 2) Set LBIST_DIAG_EN

[3] Any delay necessary to wait here?

(Step 3) Set LBIST_EN

[4] How long delay until diag complete bit set?

Example 2:

(Step 1) Open CTRL_LBIST_LOCK

Delay of several ms

(Step 2) Set LBIST_DIAG_EN

[5] Can we have a long delay here, 1 second?

(Step 3) Set LBIST_EN

[6] Does the self test run in case of long delays between LBIST_DIAG_EN and LBIST_EN and will it complete in same time as for short delay?

Thanks for your support

Regards

Florian

0 Niko Alatalo 8 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

[1] Yes this is the bit I was referencing to.

[2] Few microsecond delay should be fine as there is no real delay between the PMIC receiving the I2C data and the register changing. Only longer delay is in the LBIST completion which could be couple of milliseconds.

regards,

Niko

0 Florian Wank 8 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

thanks for your reply.

Did you get the confirmation from your team?

regards,

Florian

0 Niko Alatalo 7 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

No not yet. Let me ping the team for a reply.

regards,

Niko

0 Florian Wank 7 months ago in reply to Niko Alatalo

Prodigy 200 points

Hi Niko,

is there an update from the team?

regards,

Florian

0 Niko Alatalo 7 months ago in reply to Florian Wank

TI__Mastermind 18740 points

Hi Florian,

yes this sequence should now be correct.

regards,

Niko

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TPS65313-Q1: LBIST is only partially working