DS90UB925Q-Q1: Invalid SCL Low / High Time Setting Cause "DES ERROR(0x0C[1])"?

Kenichiro

Part Number: DS90UB925Q-Q1
Other Parts Discussed in Thread: DS90UB927Q-Q1

[ DS90UB925-Q1 & DS90UB927-Q1 ] Invalid SCL Low / High Time Setting Cause "DES ERROR(0x0C[1])"?

Hi,

My customer has seen the error behavior on their system which use DS90UB927-Q1, DS90UB928-Q1 and remote slave as drawing below.
According to the error log which is sitting next of HOST processor, when error occurrs, the DES Error flag (0x0C[1]) is triggered.

From their debug, customer has found that SCL Low tiime and High time setting of both DS90UB927-Q1 and DS90UB928-Q1 are not correct.
(it's like, they left both registers as default, even though they use 400KHz I2C communication.)

Do you think this invalid SCL Low / High Time setting cause DES Error (0x0C[1])?
It's appreciated if you can elaborate the "DES Error" itself such as details of the data package (I2C & GPIO?) which CRC checked.

My related posts

DS90UB927Q-Q1: BIST Mode and "DES Error"(0x0C[1])
e2e.ti.com/.../2459982

DS90UB927Q-Q1: BIST Related Questions
e2e.ti.com/.../2456798

Thanks,
Ken

over 7 years ago

0 Davor Glisic over 7 years ago

TI__Expert 8145 points

Hello-

Invalid SCL Low / High Time settings do not cause DES Errors.

The SCL Low / High settings are used to set the Low / High pulse times of the SCL output when the device is the I2C Master on the local I2C bus.

The DES Error is set when SER (927) receives data over FPD-Link III back-channel that is different from what was sent by DES (928).

Regards,
Davor

0 Kenichiro over 7 years ago in reply to Davor Glisic

Mastermind 9165 points

Hi Davor,

Thank you for your support.
Let me ask few more questions.

<Q1>:

When a serializer detects a DES Error (0x0C[1]), what happens on output data from serializer such as I2C and GPO?
It's assumed that serializer continues to output data with some errors or suspend output data for a while.

<Q2>:

Are there any ways to force introducing BC error which cause DES Error at serializer?

I know that DS90UB953/4 has similar force error functions. What about on UB92x?

Thanks,
Ken

0 Kenichiro over 7 years ago in reply to Kenichiro

Mastermind 9165 points

Hello Davor,

Sorry for rushing you, but can you please look into queries above?

Thanks,
Ken

0 Davor Glisic over 7 years ago in reply to Kenichiro

TI__Expert 8145 points

Hello Kenichiro,

1. Yes, the serializer continues to output data with some errors.
2. Setting the 928 register bit 0x32[0] forces a single error on the back-channel frame. Setting the 928 register bit 0x32[1] forces a single error on every back-channel frame.

Regards,
Davor

0 Kenichiro over 7 years ago in reply to Davor Glisic

Mastermind 9165 points

Hi Davor,

it's helpful information!
Let me talk with customer.

Thanks,
Ken

0 Kenichiro over 7 years ago in reply to Kenichiro

Mastermind 9165 points

Davor,

Please check the description below. Correct?

---
0x32[0]=0(Default, no error)
0x32[0]=1(forces a single error on the back-channel frame)
---
0x32[1]=0(Default, no error)
0x32[1]=1(forces a single error on every back-channel frame)
---

Also, how are these bits cleared? self-clear?

Thanks,
Ken

0 Davor Glisic over 7 years ago in reply to Kenichiro

TI__Expert 8145 points

Ken,

Yes, it is correct. Only bit 0x32[0] is a self-clearing bit.

Regards,
Davor

Interface

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DS90UB925Q-Q1: Invalid SCL Low / High Time Setting Cause "DES ERROR(0x0C[1])"?

[ DS90UB925-Q1 & DS90UB927-Q1 ] Invalid SCL Low / High Time Setting Cause "DES ERROR(0x0C[1])"?