3991 - Lattice Diamond v3.1: How to set the behavior of unused pins in an FPGA&nbsp;design?<br>

3991 - Lattice Diamond v3.1: How to set the behavior of unused pins in an FPGA&nbsp;design?<br>

Solution:

These are some of the workarounds:

1) In RTL code, assign the following attributes to the unused input:

   /* synthesis syn_force_pads=1 syn_noprune = 1 */

The 'syn_noprune' will not allow Synplify Pro to optimize unconnected I/O buffers and will increase resource utilization. So, as per your design requirement, it may or may not be used.

2) Under Strategy1 make the following setting:

    MAP Design--> Command line options = -u
    This ensures that the Mapper does not remove the unused I/Os.

3)
In spreadsheet view, make pull mode =NONE