DS90C387A: R_FB state changes after boot-up

John Li

Part Number: DS90C387A

Hi,

I would like to configure DS90C387A to do "Rising Edge Data Strobe". However, the R_FB signal is driven to logic "0" during system boot-up. Then it will be driven to logic "1" and stay as "1" as soon as the system boot-up is completed.

Would this cause problem for DS90C387A to do "Rising Edge Data Strobe" ?

Thanks!

over 7 years ago

0 Palaniappan Manickam over 7 years ago

TI__Genius 10475 points

Hello,
When left open the R_FB input is low because of the internal pull-down. If the input is high the rising data strobe edge will be selected, so you should make sure it is set to high if you like to configure it to this.

0 John Li over 7 years ago in reply to Palaniappan Manickam

Prodigy 30 points

Hi Palaniappan,

I do not understand your response. This is not relevant to my question.

The R_FB pin is always driven the entire time. My concerns is whether the R_FB pin status might be latched by DS90C387A during boot-up.

Regards,

John

Palaniappan Manickam said:
Hello,
When left open the R_FB input is low because of the internal pull-down. If the input is high the rising data strobe edge will be selected, so you should make sure it is set to high if you like to configure it to this.

0 Palaniappan Manickam over 7 years ago in reply to John Li

TI__Genius 10475 points

John,
Sorry for the delayed response.
This is an input pin, so there is no concern here regarding latching during boot-up. This should be ok.

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DS90C387A: R_FB state changes after boot-up