DDC316 can not write Cofiguration

Robert Closheim

Other Parts Discussed in Thread: DDC316

Hello,

I am using three DDC316 at one SPI.

After Power on, I can read the first Four Channles of the first DDC316.

If I try to switch the DDC316 in DaisyChain Mode by writing the Configuration Bits, DValid is still high after the last Bit.

Here is a Scope Plot:

Yellow=CLK, Blue=DIN_CFG, Green=DVALID, Red=DCLK

For a better view here again:

The CONV Signal is still by one Level.

But The DVALID Signal leves still high and nothing changed.

Has anyone a Idea what is going wrong?

Greetings Robert

Hello Admins,

excused me but I thinking I am absolutly wrong here with my question.

Would it be able to move this posting to the 'Precision Data Converters Forum', I guess it is better placed there.

Thank You, Robert

over 12 years ago

0 Tom Hendrick over 12 years ago

TI__Guru**** 171426 points

Hi Robert,

This is the correct forum for your post on the DDC316. Is the over/undershoot on the screen captures you sent real? Can you possibly post a schematic showing the connections around the DDC316?

0 Robert Closheim over 12 years ago in reply to Tom Hendrick

Prodigy 40 points

Hello Tom,

thank you for your response.

The Spikes on DIN_CFG signal are real as far as i can judge.

For signal measurement i have to put a wire on the connector pin so i am not realy sure that is real.

Here is the schematic of the DDC316:

Regards Robert

0 Robert Closheim over 12 years ago in reply to Robert Closheim

Prodigy 40 points

So, I cleand the signals form over/undershoots as well as possible.

Here is the result:

But it still not works.

I have no idea what to do now:

Any suggestions?

Regards Robert

0 Robert Closheim over 12 years ago in reply to Robert Closheim

Prodigy 40 points

Ok, now i set the SysClk from 40MHz down to 20 MHz.

Nothing helps.

Could someone explaine me step by step how to configure the DDC316.

Obviously i do something wronge but i don't see it.

Regards Robert

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DDC316 can not write Cofiguration