Intel® Quartus® Prime Standard Edition User Guide: Third-party Synthesis

ID 683796
Date 9/24/2018
Document Table of Contents Creating Black Boxes in Verilog HDL

Any design block that is not defined in the project, or included in the list of files to be read for a project, is treated as a black box by the software. Use the syn_black_box attribute to indicate that you intend to create a black box for the module. In Verilog HDL, you must provide an empty module declaration for a module that is treated as a black box.

The example shows the A.v top-level file. Follow the same procedure for lower-level files that also contain a black box for any module beneath the current level hierarchy.

Verilog HDL Black Box for Top-Level File A.v

module A (data_in, clk, e, ld, data_out);
    input data_in, clk, e, ld;
    output [15:0] data_out;

    wire [15:0] cnt_out;

    B U1 (.data_in (data_in),.clk(clk), .ld (ld),.data_out(cnt_out));
    F U2 (.d(cnt_out), .clk(clk), .e(e), .q(data_out));

    // Any other code in A.v goes here.

// Empty Module Declarations of Sub-Blocks B and F follow here.
// These module declarations (including ports) are required for black boxes.

module B (data_in, clk, ld, data_out) /* synthesis syn_black_box */ ;
    input data_in, clk, ld;
    output [15:0} data_out;

module F (d, clk, e, q) /* synthesis syn_black_box */ ;
    input [15:0] d;
    input clk, e;
    output [15:0] q;