cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Highlighted
Visitor
Visitor
5,648 Views
Registered: ‎05-09-2016

Supposed to be float or pull down but signal...

Hi everybody,

 

I get some noise for my board which disappear when I remove the FPGA.

I found out the FPGA's unused outputs provide signals...

 

 

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|Pin Number|Signal Name          |Pin Usage |Pin Name              |Direction|IO Standard|IO Bank Number|Drive (mA)|Slew Rate|Termination|IOB Delay|Voltage  |Constraint|IO Register|Signal Integrity|
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|G3        |DATA_G<8>            |IOB       |IO_L07N_3             |OUTPUT   |LVCMOS33   |3             |12        |SLOW     |NONE**     |         |         |UNLOCATED |YES        |NONE            |
|G4        |                     |DIFFSI_NDT|IP_3/VREF_3           |UNUSED   |           |3             |          |         |           |         |         |          |           |                |
|K3        |DATA_G<15>           |IOB       |IO_L15P_3/TRDY2/LHCLK6|OUTPUT   |LVCMOS33   |3             |12        |SLOW     |NONE**     |         |         |UNLOCATED |YES        |NONE            |

For example these 3 outputs. In the UCF file, there is nothing with G3, G4 or K3.

 

 

config.jpg

I well selected "Pull down" at Unused IOB Pins list. I also tried Pull up and Float, same problem, I get signal...

 

I don't know what is DIFFSI_NDT|IP_3/VREF_3 but I get this signal :

sig.jpg

 

How to really float or pull down the unused pins ? For now it feeds signal to my other components and create a noise. (maybe this is not the reason of the noise)

 

I am sure it again a simple problem, please help me.

Thank you.

Tags (1)
0 Kudos
1 Reply
Highlighted
Visitor
Visitor
5,596 Views
Registered: ‎05-09-2016

I found ISE design route output ports not located in the ucf file, randomly. Could you delete my topic ? Thank you.
0 Kudos