Basys 2 - Spartan 3e

[athulbalanea]

Hi,

 

I need help to initialise and implement an inout port in BASYS 2(Spartan 3E) FPGA board. I tried using IOBUF and assigned that port to B6 or A9 or C6.I couldn't get the result. Without using the IOBUF, i am getting the desired signal pattern as output but in milli volt range. And i'm not sure whether i able to recive or not with out using the IOBUF since I could not test it..

 

I want to implement the I2C protocol, so the sda line should be INOUT, which I cant figure out...Should I use any specific PIn in Pmods of Basys 2 as Inout port....  Please help me with this...

 

Thanks in Advance

Athul

[hamster]

Does the signal have either an external pull up resistor, have you added the PULLUP contstraint on that pin or added a PULLUP primitive to the output signal?

[athulbalanea]

Yes, I have tried using PULLUP primitive.

 I have declared the pin in UCF as shown below:

 

NET "sda" LOC = "C13"  | DRIVE = 2  | PULLUP ;

[hamster]

Well that is the correct constraint for a pin on JC. Are you sure you are measuring it correctly? What HDL code are you using to test the pin with?