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DP83867IR: 100M Link Down, Conditions for link down

Ryo Kukita

Intellectual 380 points

Part Number: DP83867IR

Hi team,

With a link up with a link partner at a media speed of 100M Full Duplex, our board links down once every few hours. The link partner side does not link down.

As a result of evaluation with 3 measuring instruments and 1 personal computer, 2 measuring instruments (same model) will be linked down.

The difference between link down and not link down is the content of bit [12: 8] in register 0x002D.

① Link down
0x002D [12: 8] = {0,0,01,1,0}
Enable FLD (0x002D, bit [15] = 1) in this state, link down immediately

② Not Link down:
0x002D [12: 8] = {0,0,01,1,0}
In this state, Enable FLD (0x002D, bit [15] = 1), no link down

Question 1: Conditions for detecting and canceling Bit10 (MLT3 Error)
Question 2: Conditions for detecting and canceling Bit9 (SNR level)
Question 3: Conditions for link down in the normal state (0x002D bit15 = 0)
　A) Does the link down condition differ depending on FLD on / off?
　B) The conditions are the same, but the threshold is different?
C) etc.

//

Thank yo.

Best Regards,

Ryo Kukita

over 4 years ago

0 Geet Modi over 4 years ago

TI__Mastermind 26320 points

Hi Ryo,

Fast link drop feature makes PHY very sensitive to errors and declares the link drop very fast ( < 10 usec). This feature is normally used for the real time Industrial applications. For regular applications, we recommend disabling the Fast Link Drop feature.

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet Modi,

Thank you for your reply.

Link down occurs once every few hours with the Fast Link Drop feature disabled,
so please advise on a workaround for this event.

//
Best Regards,
Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

Suggest following:

1. Try various lenght of cable whether that helps : 10 meter, 50 meter, 100 meters

2. Use DP83867 EVM and check whether you see similar issue.

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet,

I tried.

1. Link dwon over 80meter using cat5e Cable.
2. When I get the board, check it and tell the result.

Best Regards,

Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

sure.. we will wait for results.

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet,

Repeat link up and link down with a cable of 80 meters or more.
From this result, is there any way to avoid link down?
Also, is there anything I should do to get additional information?

EVM will be available on October 15th.

//

Best Regards,

Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

Can you please summarise test results in a table with various conditions you are changing across this test. Otherwise it's difficult to follow and get a complete understanding of the issue.

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi, Geet

sory for my late reply.

Please check the attached file that summarizes the test results.

A) Link down with 100M if link partners are Equip 1 and 2
　1. Input rate doesn't matter
　2. Auto-negotiation enabled / disabled does not matter
3. SNR Level, MLT3 Error occurs (when set to 0x002d [4: 0] = 0x1f)
4. 100/1000M keeps Link up
B) Link up with 100M if link partners are Equip 3 and 4
1. SNR Level, MLT3 Error does not occur (when set to 0x002d [4: 0] = 0x1f)
2. 10/100/1000M keeps Link up

/cfs-file/__key/communityserver-discussions-components-files/138/Summary-of-test-results.xlsx

//----

best regards,

Ryo Kukita.

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

Thanks for details.

1. My board refers to board with DP83867.

2. In xls, can you please explain what does "A.N.: stands for ? As I see with A.N. disable the performance with your board is good.

3. With DP83867 EVM, did you kept the Fast Link Drop enabled or disabled?

4. Have you disabled 1000M and liking the PHY with 100M speed only ?

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

Ans1 : My board is a prototype board that implements DP83867IR.
Ans2 : "A.N" means auto-negotiation.
Ans3 : Fast Link Drop disabled.
Ans4 : sorry, about my previous post(oct,19), correct "4. 100/1000M keeps Link up" to "10/1000M keeps Link Up".

The attached file has been updated.

/cfs-file/__key/communityserver-discussions-components-files/138/Summary-of-test-results_5F00_v2.xlsx

Summary of issue
if Link Partener is Equip1/2 and Media Speed is 100M only, Link Down once in few hours.
similar issue seems to My Board and EVM.

best regards

Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

We don't such behaviour on our boards. Can you try testing the DP83867 EVM and your board with DP83867 ? Also, can you collect register 0x00 to 0x1F dump for both linkup and link down scenario.

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet,

Please wait until November 4th to collect the registers.
Since the link-up is maintained for a certain period of time, the register of the link-up scenario can be collected, but since the link-down occurs only for a moment, I do not know if it can be obtained.

I'm guessing this issue is in MLT3 error and SNR level.
Assuming these alarms are occurring due to poor input signal quality, is there any information that can be obtained by collecting register settings?

Best Regards,

Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

EVMs are tested for upto 120 meters of CAT5e cable. The SNR level issue with good cable upto 100-120 meters is not expected.

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet,

Leading the register at 100M link up.

/cfs-file/__key/communityserver-discussions-components-files/138/PHY_5F00_REG_5F00_READ.xlsx

Best Regards,

Ryo Kukita

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

If you look at register 0x005 content, the EVM is receiving the Link Partner Negotiation Capability while the GbE is not recieving. This is causing GbE not link-up.

You need to identify the difference between two board for the reason.

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

The difference between two board is that the GBE setting is fixed at 100M.
The result of reading with auto-negotiation enabled is attached.
The register 0x005 content matched between EVM and GBE.

/cfs-file/__key/communityserver-discussions-components-files/138/PHY_5F00_REG_5F00_READ_5F00_2.xlsx

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

I believe you are looking for gigabit link. can you share the register dumpes with 1Gbe enabled on both EVM and your board.

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

I Dumped register contents 3 times in the linked up state on both EVM and GBE.

Please check it.

/cfs-file/__key/communityserver-discussions-components-files/138/PHY_5F00_REG_5F00_READ_5F00_3.xlsx

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

The logs shared are for the good scenario only. However I believe you have scenario where the link comes and link down. I want to see the logs captures in following sequence;

1. Dump log before Link-up

2. Dump log once link is up

3. Dump log once the link is down.

Also, additional question:

a. Do router have EEE ( Energy Efficient Enabled ) ?

b. What's the cable length you are using ?

c. Do you see the issue when 2x DP83867 are connected to each other ?

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

measurment condition:

a. DUT(EVM and GBE) setting
Auto-Negotiation active
advertisement full support

b. Link Partner
Auto-Negotiation active
advertisement exclude 1000M

Dump log :
Sequence No1 and No2 complete.
Seq.No1 : dis connect cable

Seq.No2 : connect cable
Sequence No3 log , waiting for link-down .

If a link down occurs, I will get a log and report the result.

/cfs-file/__key/communityserver-discussions-components-files/138/PHY_5F00_REG_5F00_READ_5F00_4.xlsx

answer :
a. router do not have EEE.
b. 3 meter , cate 5e
c. I do not see the issue

This issue only occurs if the link partner is a particular instrument.

That instrument implements PHY "VSC8244XHG".

Best Regards,

Ryo

0 Ryo Kukita over 4 years ago in reply to Ryo Kukita

Intellectual 380 points

Hi Geet

A link down occurred on the GBE board, but the link down recovers immediately,so it is not possible to dump the logs during the link down.

Therefore, the attached content (column H) will be the log captured for the first time after the link down occurred.

/cfs-file/__key/communityserver-discussions-components-files/138/PHY_5F00_REG_5F00_READ_5F00_4a.xlsx

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

HI Ryo,

DP83867 is tested at 3P Compliance test house for Inter Operability with multiple link partners and have passing report.

Question :

a) WIth DP83867 EVM also, you see constant link drop with VSC8244 ?

b) Did you try some other PHY linking with VSC8244 ?

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

I've acknowledged that DP83867 tests inter Operability with multiple link partners.

Answer:
a) Less than GBE boards, but Yes
b) No, I will try it with measuring instrument "SmartBits200".

Best Regards,

Ryo

0 Ryo Kukita over 4 years ago in reply to Ryo Kukita

Intellectual 380 points

Hi Geet

I connected my board(GBE) and Smartbits200 with 100BTx during 3days.

Result : No Link-Down

Smatbits200 implement "LEVEL ONE"'s "LXT970AQC".

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

In this scenario, you may want to take up the issue with VSC device ?

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi, Geet

Yes, there is a problem on the measuring instrument side (VSC8244),

and I think that there is a high possibility that there is no workaround on my board (DP83867IR) side.

In this case, similar problems occur in product inspection and field, so a workaround is needed.

1) Workaround for product inspection
Use other measuring instruments
2) Workaround for field failures
Explain to the customer that there is a problem with the link partner.

However, it is necessary to investigate the cause of the problem.

Therefore, by presenting the link down condition of 100BTx,Consider how to capture the signal quality of the VSC8244 and the details of the event.
Please give us some advice when considering it.

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

You can use IEEE Compliance software to run the Transmitter test to check the quality of the signal from VSC8244. Further you can ask the InterOP test reports from VSC8244.

Regards,

Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi,Geet

I requested the manufacturer's agency to conduct a compliance test and present a test report, but it was refused.

In addition, the VSC8244 compliance test cannot be conducted for the following reasons.
　・ There is no evaluation board for VSC8244
　・ The control method of the measuring instrument equipped with VSC8244 is not open to the user.

Could you please tell me the link down condition of DP83867 that my FAE also requests?

Best Regards,

Ryo

0 Geet Modi over 4 years ago in reply to Ryo Kukita

TI__Mastermind 26320 points

Hi Ryo,

On VSC8244, I am not sure how can we help you with ?

On Link down condition, Can you please open new thread for the question ?

Regards,
Geet

0 Ryo Kukita over 4 years ago in reply to Geet Modi

Intellectual 380 points

Hi Geet

OK, I open new thread.

Best Regards

Ryo