Spartan-6 FPGA SelectIO Resources User Guide notes 2 SelectIO attributes/constraints

1.Location Constraint for assigning I/O ports

NET <I/O_NAME> LOC = "<EXTERNAL_PORT_IDENTIFIER>";

Example:

NET My_io loc=r7;

2.IOSTANDARD Attribute for selecting IO standards such as LVCMOS25,LVDS_25, etc.

NET <I/O_NAME> iostandard= "<iostandard value>";

3.Output Slew Rate Attributec

NET <I/O_NAME> SLEW = "<SLEW_VALUE>";

Slew_value can SLOW (Default) FAST Quietio

4.Output Drive Strength Attribute driving capacity (MA)

NET <I/O_NAME> drive = "<DRIVE_VALUE>";

Drive_value can 2 4 6 8 (Default) 16 24

5.pullup/pulldown/keeper for Ibuf, Obuft, and IOBUF
NET <I/O_NAME> <PULLUP/PULLDOWN/KEEPER>;

Spartan-6 FPGA SelectIO Resources User Guide notes 2 SelectIO attributes/constraints