fa_st_block.vst

来自「i need of vhdl code for 32-bit risc proc」· VST 代码 · 共 44 行

ENTITY fa_st_block IS
PORT (
ai : IN BIT;
bi : IN BIT;
cia : IN BIT;
si : OUT BIT;
gi : OUT BIT;
pi : OUT BIT);
END fa_at_block ;

ARCHITECTURE fablock_st_arch OF fa_st_block IS

COMPONENT xorgate
PORT ( a1 : IN BIT ;
       b1 : IN BIT ;
       c1 : IN BIT ;
       d1 : OUT BIT
);

COMPONENT  andgate 
PORT ( a2 : IN BIT ;
       b2 : IN BIT ;
       c2 : IN BIT 
);

COMPONENT orgate 
PORT ( a3 : IN BIT ;
       b3 : IN BIT ;
       c3 : OUT BIT
);


BEGIN

-- Structural Description of FA block
 
xor1 : xorgate PORT MAP(ai,bi,cia,si);
and1 : andgate PORT MAP(ai,bi,gi);
or1  : orgate PORT  MAP(ai,bi,pi);
--si <= ai XOR bi XOR cia ;
--gi <= ai AND bi ;
--pi <= ai OR bi ;
END;