Flexible interface that supports scaler or arrays

SystemVerilog
,
3

In reply to dave_59:

Also consider using an interface type parameter instead.

interface foo_if
#(
   type atom_t = bit [ 7 : 0 ]
);
//...

  localparam int ATOM_DIMENSIONS = $dimensions( atom_t );  
  localparam int ATOM_ELEMENT_SIZE = $size( atom_t, ATOM_DIMENSIONS );
  localparam int TOTAL_ELEMENTS =  $bits( atom_t ) / ATOM_ELEMENT_SIZE;

  atom_t my_data;
//...
endinterface

The default “atom_t” works with a single dimensional (8-bit scaler). But, the interface can support different sized scalers, as was as n-dimensional arrays (of varying types) - all controlled by the parameter type passed in from the parent interface instantiation. i.e.

module top;
  typedef bit [ 2 : 0 ][ 7 : 0 ] my_pixel_t;
  foo_if #( .atom_t( my_pixel_t ) ) rgb_pixel_if();
endmodule

I use these quite a lot - however for ease, I tend to require atom_t to be a packed typed. I’ve even used packed structures in the parameter type override.