DS125DF1610: CDR lock issue

cannie chang

Intellectual 910 points

Part Number: DS125DF1610

Hi sir,

When I use multi-point application, I have one issue need your help. Please check attach file. my configure is

6A 96 --> 1D 9B-->01

6B 96 --> 1D 9B --> 01

7A 96 --> 1C 9B -->00

7B 96 -->1C 9B -->00

signal come from 6A and 6B. Now, 6A broadcast to 7A 6B broadcast to 7B.

now, 6A CDR is lock, why 7A is unlock.

Thanks

cannie

ds125df1610.doc

over 6 years ago

0 Nasser Mohammadi over 6 years ago

TI__Guru* 93670 points

Hi Cannie,

Based on your GUI picture, TX6A and TX6B CDRs are both locked to 6B input signal.

TX7A CDR has signal detect but is not locked to signal on input 6A.

Meanwhile TX7B CDR is locked to input 6A signal.

Please check to make sure you have setup CDR 7A using the same rate and CTLE settings as CDR 7B.

Regards,,nasser

0 cannie chang over 6 years ago in reply to Nasser Mohammadi

Intellectual 910 points

Hi,

It seem very hard to lock all 4 CDR. at 6B 6B 6A 6A sequence in cross point. with same setting change to 6B6A6A6B, it will be OK. Please help to check. I have 4 block, only this block can not lock well.

No matter, I dis-connect and connect back. Please help to check! does it will be block by some combination.

Br,

cannie0285.ds125df1610.doc

0 cannie chang over 6 years ago in reply to Nasser Mohammadi

Intellectual 910 points

4606.ds125df1610.doc

0 Nasser Mohammadi over 6 years ago in reply to cannie chang

TI__Guru* 93670 points

Hi Cannie,

1). When channel TX7A is not locking - using input Rx 6A, can you force Rx/DFE CTLE settings to 0x00 to get Tx7A CDR to lock? In this configuration, you can optimize or change Tx7A CTLE settings - using RxEQ/DFE tab - until you get the device to lock.

2). In 2nd experiment, force CTLE to adapt mode 0 with 0x00 setting or a bit higher for all devices. Do we achieve lock under this condition?

3). Is this 10GbE or 1.25GE?

Regards,,nasser

0 cannie chang over 6 years ago in reply to Nasser Mohammadi

Intellectual 910 points

Hi,

Please check attach file5482.ds125df1610.doc

0 Nasser Mohammadi over 6 years ago in reply to cannie chang

TI__Guru* 93670 points

Hi Cannie,

Please below note responses to your questions:

After you connect 6B signal, you can use Rx EQ/DFE tab to optimize CTLE settings until CDR gets locked. Please note after you make CTLE changes you have to click on “Apply to All Channels” and then click on “Reset CDR All Channels”.

You can use Adapt Mode 0, No Adapt/Manual Mode and set CTLE boost settings.

Please send me email at nasser.mohammadi@ti.com so we can have one of our application engineer to help you with this.

Regards,,,nasser

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DS125DF1610: CDR lock issue