AM437x SYSBOOT pin external pullup/pulldown

Michi Yama

Hi,

I have one question regarding sysboot pins of AM437x.

If some SYSBOOT pin for my boot does not influence, those pins does not need external pull up /down (level is floating).

For example, IF NAND boot is used, SYSBOOT [18, 16,11,9,5] pins are "don't care". Are these pins allowed the open?

Please advise me.

I appreciate your quick reply.

Best regards,

Michi

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

Yes, this is allowed.

0 peaves over 8 years ago in reply to Biser Gatchev-XID

TI__Guru 60905 points

The answer Biser provided is partially true.

The state of some SYSBOOT inputs may not be relevant for a specific boot mode and in this case they can be either a logic high or logic low. However, you should never leave any inputs floating. Since the SYSBOOT inputs do not have internal pull resistors turned on by default, you must use external resistors to pull theses inputs to valid logic levels.

Regards,
Paul

0 Michi Yama over 8 years ago in reply to peaves

Guru 10030 points

Dear Paul-san,

Thank you for your additional information.

I will take care of all SYSBOOT inputs to keep valid logic levels.

Best regards,
Michi

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AM437x SYSBOOT pin external pullup/pulldown