Subversion Repositories idea

-- File Name   : fsub.vbe                                       -- 
-- Description : The full subtractor                            --
-- Purpose     : To be used by ASIMUT and SCMAP                 --
-- Date        : Aug 22, 2001                                   --
-- Version     : 1.1                                            --
-- Author      : Martadinata A.                                 --
-- Address     : VLSI RG, Dept. of Electrical Engineering ITB,  --
--               Bandung, Indonesia                             --
-- E-mail      : marta@ic.vlsi.itb.ac.id                        --

entity fsub is
port(
  a       : in   bit;   
  b       : in   bit;
  bin     : in   bit;
  d       : out  bit;  
  bout    : out  bit; 
  vdd     : in   bit;   
  vss     : in   bit    
  );
end fsub;

architecture vbe of fsub is

begin
  assert ((vdd and not (vss)) = '1')
    report "power supply is missing on fsub1"
    severity warning;
  
  d    <= (a xor b) xor bin;
  bout <= ((not a) and b) or ((not a) and bin) or (b and bin); 

end;