Intel® Hyperflex™ Architecture High-Performance Design Handbook

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ID 683353
Date 10/04/2021
Public
Document Table of Contents

7.1.2. Black-boxing VHDL Modules

In black-boxing VHDL, keep the entity as-is, but delete the architecture. In the case when you have multiple architectures, make sure you remove all of them.

Before:

-- k-bit 2-to-1 multiplexer
LIBRARY ieee ;
USE ieee.std_logic_1164.all ;

ENTITY mux2tol IS
GENERIC ( k : INTEGER := 8) ;
    PORT (    V, W : IN    STD_LOGIC_VECTOR(k-1 DOWNTO 0) ;
              Sel  : IN    STD_LOGIC ;
              F    : OUT   STD_LOGIC_VECTOR(k-1 DOWNTO 0) ) ;
END mux2tol ;

ARCHITECTURE Behavior OF mux2to1 IS
BEGIN
    PROCESS ( V, W, Sel )
    BEGIN
        IF Sel = '0' THEN
            F <= V ;
        ELSE
            F <= W ;
        END IF ;
    END PROCESS ;
END Behavior ;

After:

-- k-bit 2-to-1 multiplexer
LIBRARY ieee ;
USE ieee.std_logic_1164.all ;

ENTITY mux2tol IS
GENERIC ( k : INTEGER := 8) ;
    PORT (    V, W : IN    STD_LOGIC_VECTOR(k-1 DOWNTO 0) ;
              Sel  : IN    STD_LOGIC ;
              F    : OUT   STD_LOGIC_VECTOR(k-1 DOWNTO 0) ) ;
END mux2tol ;

ARCHITECTURE Behavior OF mux2to1 IS
BEGIN
END Behavior ;

In addition to black-boxing modules, you must assign the modules to a an empty design partition. The partition prevents the logic connected to the black-boxed modules from being optimized away during synthesis.

To create a new partition:

  1. In the Project Navigator Hierarchy tab, right-click the black-boxed module, and then click Design Partition > Set as Design Partition.
  2. For Empty, select Yes.
  3. Add all the black-box modules into this partition.
    Figure 133. Create New Empty Partition

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