SN75DP130 Pre-Emphasis Level Verification Testing Fail

Prescott Siao

Other Parts Discussed in Thread: SN75DP130

Hi Team,

Could you please let me know who take care SN75DP130 issue?

My customer, did the DP testing and got the fail result.

HD263&XTC3-4C2U1F1A Lane0&1_20141120_184819 is shown the testing result under default setting. (Pre-Emphasis Level Verification Testing Fail)

So I recommend customer to set the DP130 local register 15’h = 0x10’h. to increase pre-emphasis.

Then run the testing again.

TekExpress Display Port report_ DUT001 is shown the testing result after set the DP130 local register 15’h = 0x10’h. (Pre-Emphasis Level Verification Testing Fail Again)

Please give some feedback on this issue.

Many thanks.

over 10 years ago

0 Elias Villegas M. over 10 years ago

TI__Guru* 76130 points

Hello Prescott,
We are analyzing the test report and we'll provide feedback as soon as possible.
Regards

0 Prescott Siao over 10 years ago in reply to Elias Villegas M.

TI__Intellectual 2220 points

Hi Elias,

Any update for this issue?

Thanks.

Prescott

0 Elias Villegas M. over 10 years ago in reply to Prescott Siao

TI__Guru* 76130 points

Hello,
Some thoughts about this:
"The compliance testing tests different levels of pre-emphasis so setting the device to a single pre-emphasis level won’t pass all testing.

Is the customer testing with link training enabled? (Reg. 04h, bit 2)

Can the customer change BOOST (Reg. 15h, bits 4:3) to 00 or 10?

If the customer is selecting pre-emphasis levels (link training disabled), they will need to program the correct pre-emphasis level with each test to match the requested level to be tested."

Regards

0 Prescott Siao over 10 years ago in reply to Elias Villegas M.

TI__Intellectual 2220 points

Hi Elias,
Thanks for your feedback.
Customer is testing with link training enabled, Reg. 04h, bit 2 = 1'b.
As the testing reports, customer got the fail results with Reg. 15h, bits 4:3 = 10'b or 01'b.
I will ask customer to try Reg. 15h, bits 4:3 = 00'b

Regards,
Prescott

0 Prescott Siao over 10 years ago in reply to Elias Villegas M.

TI__Intellectual 2220 points

Hi Elias,

Thanks for your response.

Customer checked the local Reg. 04h, bit 2 = 1'b (link training enabled).

And referred to change BOOST (Reg. 15h, bits 4:3) to 00 or 10.

But the authentication reports are still showed “FAIL.”

Below link are the testing report for Reg. 15h, bits 4:3 = 00 & 10.

DUT1_setting bits=00_pre-emphasis authencation on DP_20150212_130804

DUT1_setting bits=10_pre-emphasis authencation on DP_20150212_162905

Could you please help to check the testing report and give some comment?

Many thanks.

0 Elias Villegas M. over 10 years ago in reply to Prescott Siao

TI__Guru* 76130 points

Hello,

"Report shows failures a 6dB and 9dB pre-emphasis ratio. I recommend looking at layout. Minimize impedance discontinues. Could also try raising the supply voltage some."

Regards

Interface

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SN75DP130 Pre-Emphasis Level Verification Testing Fail