DM646x I/O port

Hi,

Thankyou Brad Griffis,
Actually I am worried about the (NC) Not Connected pins,
I thought I can use the internal pulldown resistors to avoid floating condition,
but I am not getting the proper results.

Please let me know what value of resistors would you recommend for external pulldown.

Thankyou and Regards.

10k is fine when complimenting the internal pullup/down.  If opposing use something stronger like 2k.

By the way, which specific pins are giving you trouble?  Is there a trace connected to it, e.g. some kind of test point?  How long?

Thankyou very much for your support.

Actually more than 8 pins (6,7,16 to 19,20,21) are giving  trouble.
I understood that pins 16 to 19 can be multiplexed with PCI mode, as I am using these for PCI communication
an external resistor should be connected(according to my understanding from the datasheet).
But I am using pins 20,21 aslo in PCI mode,should I use an external resistor in this case also?

By the way I don't  know much about PCI communication,is it necessary to connect external resistor to the pins which are used in PCI mode.Actually regarding the pins multiplexed with the PCI comm,the trouble occurs after the POR Reset and continues until Power OFF.

And for the safety purpose I am thinking of using external resistors for all the remaining No Connection(NC) pins,
please let me know your suggestion.

Regards.

I don't recognize those pins numbers.  The pins have a letter and a number to identify them.  I thought maybe you were talking about GP[16], etc. but that particular pin is not muxed with PCI so I couldn't follow what you were talking about.  Also, I'm confused because you previously stated the pins in question were no connects, but above it sounds as if they are being used for PCI.

I am sorry for the confusion,
that was the question from our client.

Actually, previously the problem occured only with the (NC) No Connection GPIO pins GP[6] and GP[7].
(Even though these pins(pins with IPD) are NC in the application,the voltage measured at these pins is more than 1.4V)

And regarding the other pins which are used for PCI communication,
I know that GP[16] to GP[19] are not muxed with PCI,but our client is using it for PCI communication.
and the trouble with these pins occurs after POR Reset and continues until Power OFF.
(the voltage measured at these pins is more than 1.6V when there is no PCI comm)

Please let me If this information is insufficent,

Regards.

If you have a trace connected to the pin then it is not a "no connect", and it would require an external resistor for purposes of config pins, etc.

GP[6] and GP[7] would be affected by the state of the VADJEN pin at reset.  If VADJEN=1 at reset then those pins will be outputs and driven according to the SmartReflex.  If something else is also driving those pins you may be seeing an intermediate voltage due to contention.

Thankyou,

Actually there was a small trace(10mm) connected to the pin,I have decided to use ext resistor.

Regards.