DS250DF230: DS250DF230: If the retimer register address is at the default setting, how many samples per pixel?

Takashi Yasuno

Prodigy 50 points

Part Number: DS250DF230
Other Parts Discussed in Thread: DS110DF111, DS110DF410

Tool/software:

To whom it may concern,

If the DS250DF230 register address is at the default setting, how many samples per pixel?

I look forward to hearing from you soon.

Thank you.

Best regards,

Takashi

6 months ago

0 David Waier 6 months ago

TI__Mastermind 20901 points

Hello Takashi,

It is currently a holiday in the US, so responses will be delayed. Please anticipate a reply on this inquiry early next week.

Best,
David

0 Takashi Yasuno 6 months ago

Prodigy 50 points

Hello David,

Please reply in the same way for DS110DF111.

Best,

Takashi

0 David Waier 6 months ago in reply to Takashi Yasuno

TI__Mastermind 20901 points

Hello Takashi,

The engineering team supporting this device will be able to help with this inquiry during this week.

Could you please help to clarify your meaning of samples per pixel? Are you referring to the eye opening monitor of the device, or a different functional block?

Best,
David

0 Takashi Yasuno 6 months ago in reply to David Waier

Prodigy 50 points

Hello David,

The meaning of samples per pixel is the number of samples for the eye opening monitor of the device.

Best,

Takashi

0 Drew Miller1 6 months ago in reply to Takashi Yasuno

TI__Mastermind 37043 points

Hi Takashi-san,

The default EOM timer setting will measure a single "pixel" in the eye for 3.25E-4 seconds (for 25.71825 Gbps).

Please see table 7-20 in the programming guide for more details. If you don't have the programming guide, you can request access here:

https://www.ti.com/drr/opn/DS250DF230-DESIGN

Thanks,

Drew

0 Takashi Yasuno 6 months ago in reply to Drew Miller1

Prodigy 50 points

Hello Drew,

Thank you for your answer.

Could you also tell me about the default EOM timer setting for the DS110DF111 ?

Best,

Takashi

0 Drew Miller1 6 months ago in reply to Takashi Yasuno

TI__Mastermind 37043 points

Hi Takashi-san,

Please see the thread below. The same is applicable for DS110DF111.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/286161/ds110df410---eom-timer-threshold?tisearch=e2e-sitesearch&keymatch=ds1%252A%2520AND%2520%2522eom%2520timer%2522#

Thanks,

Drew

0 Takashi Yasuno 6 months ago in reply to Drew Miller1

Prodigy 50 points

Hello Drew,

Thank you for your answer.

For 10.3125 Gbps, the sampling time is stated to be 610us.

That means the sampling rate is 1640 times per second.

However, on page 25 of the datasheet it says:

”When this value is
set to its maximum possible value of 0xff, the maximum number of samples acquired at each phase and
amplitude offset is approximately 218.”

Excuse me, but is the calculation formula in the thread correct ?

Best,

Takashi

0 Drew Miller1 6 months ago in reply to Takashi Yasuno

TI__Mastermind 37043 points

Hi Takashi,

I am looking into this. Please note that 218 is a typo and should be 2^18. This can be seen in DS110DF410 data sheet.

Thanks,

Drew

0 Drew Miller1 5 months ago in reply to Drew Miller1

TI__Mastermind 37043 points

Hi Takashi,

I wanted to close the loop on this. Unfortunately, I was not able to get additional clarity on this for DS110DF111.

Thanks,
Drew

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DS250DF230: DS250DF230: If the retimer register address is at the default setting, how many samples per pixel?