?? 66_signed.vhd
字號:
variable one_bit : STD_ULOGIC;
variable result : STD_LOGIC_VECTOR (A'range);
begin
for i in A'range loop
if (IS_X(A(i))) then
assert false
report "There is an 'U'|'X'|'W'|'Z'|'-' in an arithmetic operand, the result will be 'X'(es)."
severity warning;
result := (others => 'X');
return result;
end if;
result(i) := tbl_BINARY(A(i));
end loop;
return result;
end;
-- Type propagation function which returns a signed type with the
-- size of the left arg.
function LEFT_SIGNED_ARG(A,B: SIGNED) return SIGNED is
variable Z: SIGNED (A'left downto 0);
-- pragma return_port_name Z
begin
return(Z);
end;
-- Type propagation function which returns an unsigned type with the
-- size of the left arg.
function LEFT_UNSIGNED_ARG(A,B: UNSIGNED) return UNSIGNED is
variable Z: UNSIGNED (A'left downto 0);
-- pragma return_port_name Z
begin
return(Z);
end;
-- Type propagation function which returns a signed type with the
-- size of the result of a signed multiplication
function MULT_SIGNED_ARG(A,B: SIGNED) return SIGNED is
variable Z: SIGNED ((A'length+B'length-1) downto 0);
-- pragma return_port_name Z
begin
return(Z);
end;
-- Type propagation function which returns an unsigned type with the
-- size of the result of a unsigned multiplication
function MULT_UNSIGNED_ARG(A,B: UNSIGNED) return UNSIGNED is
variable Z: UNSIGNED ((A'length+B'length-1) downto 0);
-- pragma return_port_name Z
begin
return(Z);
end;
function mult(A,B: SIGNED) return SIGNED is
variable BA: SIGNED((A'length+B'length-1) downto 0);
variable PA: SIGNED((A'length+B'length-1) downto 0);
variable AA: SIGNED(A'length downto 0);
variable neg: STD_ULOGIC;
constant one : UNSIGNED(1 downto 0) := "01";
-- pragma map_to_operator MULT_TC_OP
-- pragma type_function MULT_SIGNED_ARG
-- pragma return_port_name Z
begin
if (A(A'left) = 'X' or B(B'left) = 'X') then
PA := (others => 'X');
return(PA);
end if;
PA := (others => '0');
neg := B(B'left) xor A(A'left);
BA := CONV_SIGNED(('0' & SIGNED' (ABS(B))),(A'length+B'length));
AA := '0' & ABS(A);
for i in 0 to A'length-1 loop
if AA(i) = '1' then
PA := PA+BA;
end if;
BA := SHL(BA,one);
end loop;
if (neg= '1') then
return(-PA);
else
return(PA);
end if;
end;
function mult(A,B: UNSIGNED) return UNSIGNED is
variable BA: UNSIGNED((A'length+B'length-1) downto 0);
variable PA: UNSIGNED((A'length+B'length-1) downto 0);
constant one : UNSIGNED(1 downto 0) := "01";
-- pragma map_to_operator MULT_UNS_OP
-- pragma type_function MULT_UNSIGNED_ARG
-- pragma return_port_name Z
begin
if (A(A'left) = 'X' or B(B'left) = 'X') then
PA := (others => 'X');
return(PA);
end if;
PA := (others => '0');
BA := CONV_UNSIGNED(B,(A'length+B'length));
for i in 0 to A'length-1 loop
if A(i) = '1' then
PA := PA+BA;
end if;
BA := SHL(BA,one);
end loop;
return(PA);
end;
-- subtract two signed numbers of the same length
-- both arrays must have range (msb downto 0)
function minus(A, B: SIGNED) return SIGNED is
variable carry: STD_ULOGIC;
variable BV: STD_ULOGIC_VECTOR (A'left downto 0);
variable sum: SIGNED (A'left downto 0);
-- pragma map_to_operator SUB_TC_OP
-- pragma type_function LEFT_SIGNED_ARG
-- pragma return_port_name Z
begin
if (A(A'left) = 'X' or B(B'left) = 'X') then
sum := (others => 'X');
return(sum);
end if;
carry := '1';
BV := not STD_ULOGIC_VECTOR(B);
for i in 0 to A'left loop
sum(i) := A(i) xor BV(i) xor carry;
carry := (A(i) and BV(i)) or
(A(i) and carry) or
(carry and BV(i));
end loop;
return sum;
end;
-- add two signed numbers of the same length
-- both arrays must have range (msb downto 0)
function plus(A, B: SIGNED) return SIGNED is
variable carry: STD_ULOGIC;
variable BV, sum: SIGNED (A'left downto 0);
-- pragma map_to_operator ADD_TC_OP
-- pragma type_function LEFT_SIGNED_ARG
-- pragma return_port_name Z
begin
if (A(A'left) = 'X' or B(B'left) = 'X') then
sum := (others => 'X');
return(sum);
end if;
carry := '0';
BV := B;
for i in 0 to A'left loop
sum(i) := A(i) xor BV(i) xor carry;
carry := (A(i) and BV(i)) or
(A(i) and carry) or
(carry and BV(i));
end loop;
return sum;
end;
-- subtract two unsigned numbers of the same length
-- both arrays must have range (msb downto 0)
function unsigned_minus(A, B: UNSIGNED) return UNSIGNED is
variable carry: STD_ULOGIC;
variable BV: STD_ULOGIC_VECTOR (A'left downto 0);
variable sum: UNSIGNED (A'left downto 0);
-- pragma map_to_operator SUB_UNS_OP
-- pragma type_function LEFT_UNSIGNED_ARG
-- pragma return_port_name Z
if (A(A'left) = 'X' or B(B'left) = 'X') then
sum := (others => 'X');
return(sum);
end if;
carry := '1';
BV := not STD_ULOGIC_VECTOR(B);
for i in 0 to A'left loop
sum(i) := A(i) xor BV(i) xor carry;
carry := (A(i) and BV(i)) or
(A(i) and carry) or
(carry and BV(i));
end loop;
return sum;
end;
-- add two unsigned numbers of the same length
-- both arrays must have range (msb downto 0)
function unsigned_plus(A, B: UNSIGNED) return UNSIGNED is
variable carry: STD_ULOGIC;
variable BV, sum: UNSIGNED (A'left downto 0);
-- pragma map_to_operator ADD_UNS_OP
-- pragma type_function LEFT_UNSIGNED_ARG
-- pragma return_port_name Z
begin
if (A(A'left) = 'X' or B(B'left) = 'X') then
sum := (others => 'X');
return(sum);
end if;
carry := '0';
BV := B;
for i in 0 to A'left loop
sum(i) := A(i) xor BV(i) xor carry;
carry := (A(i) and BV(i)) or
(A(i) and carry) or
(carry and BV(i));
end loop;
return sum;
end;
function "*"(L: SIGNED; R: SIGNED) return SIGNED is
-- pragma label_applies_to mult
begin
return mult(CONV_SIGNED(L, L'length),
CONV_SIGNED(R, R'length)); -- pragma label mult
end;
function "*"(L: UNSIGNED; R: UNSIGNED) return UNSIGNED is
-- pragma label_applies_to mult
begin
return mult(CONV_UNSIGNED(L, L'length),
CONV_UNSIGNED(R, R'length)); -- pragma label mult
end;
function "*"(L: UNSIGNED; R: SIGNED) return SIGNED is
-- pragma label_applies_to plus
begin
return mult(CONV_SIGNED(L, L'length+1),
CONV_SIGNED(R, R'length)); -- pragma label mult
end;
function "*"(L: SIGNED; R: UNSIGNED) return SIGNED is
-- pragma label_applies_to plus
begin
return mult(CONV_SIGNED(L, L'length),
CONV_SIGNED(R, R'length+1)); -- pragma label mult
end;
function "*"(L: SIGNED; R: SIGNED) return STD_LOGIC_VECTOR is
-- pragma label_applies_to mult
begin
return STD_LOGIC_VECTOR (mult(CONV_SIGNED(L, L'length),
CONV_SIGNED(R, R'length))); -- pragma label mult
end;
function "*"(L: UNSIGNED; R: UNSIGNED) return STD_LOGIC_VECTOR is
-- pragma label_applies_to mult
begin
return STD_LOGIC_VECTOR (mult(CONV_UNSIGNED(L, L'length),
CONV_UNSIGNED(R, R'length))); -- pragma label mult
end;
function "*"(L: UNSIGNED; R: SIGNED) return STD_LOGIC_VECTOR is
-- pragma label_applies_to plus
begin
return STD_LOGIC_VECTOR (mult(CONV_SIGNED(L, L'length+1),
CONV_SIGNED(R, R'length))); -- pragma label mult
end;
function "*"(L: SIGNED; R: UNSIGNED) return STD_LOGIC_VECTOR is
-- pragma label_applies_to plus
begin
return STD_LOGIC_VECTOR (mult(CONV_SIGNED(L, L'length),
CONV_SIGNED(R, R'length+1))); -- pragma label mult
end;
function "+"(L: UNSIGNED; R: UNSIGNED) return UNSIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := max(L'length, R'length);
begin
return unsigned_plus(CONV_UNSIGNED(L, length),
CONV_UNSIGNED(R, length)); -- pragma label plus
end;
function "+"(L: SIGNED; R: SIGNED) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := max(L'length, R'length);
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: UNSIGNED; R: SIGNED) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := max(L'length + 1, R'length);
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: SIGNED; R: UNSIGNED) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := max(L'length, R'length + 1);
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: UNSIGNED; R: INTEGER) return UNSIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := L'length + 1;
begin
return CONV_UNSIGNED(
plus( -- pragma label plus
CONV_SIGNED(L, length),
CONV_SIGNED(R, length)),
length-1);
end;
function "+"(L: INTEGER; R: UNSIGNED) return UNSIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := R'length + 1;
begin
return CONV_UNSIGNED(
plus( -- pragma label plus
CONV_SIGNED(L, length),
CONV_SIGNED(R, length)),
length-1);
end;
function "+"(L: SIGNED; R: INTEGER) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := L'length;
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: INTEGER; R: SIGNED) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := R'length;
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: UNSIGNED; R: STD_ULOGIC) return UNSIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := L'length;
begin
return unsigned_plus(CONV_UNSIGNED(L, length),
CONV_UNSIGNED(R, length)) ; -- pragma label plus
end;
function "+"(L: STD_ULOGIC; R: UNSIGNED) return UNSIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := R'length;
begin
return unsigned_plus(CONV_UNSIGNED(L, length),
CONV_UNSIGNED(R, length)); -- pragma label plus
end;
function "+"(L: SIGNED; R: STD_ULOGIC) return SIGNED is
-- pragma label_applies_to plus
constant length: INTEGER := L'length;
begin
return plus(CONV_SIGNED(L, length),
CONV_SIGNED(R, length)); -- pragma label plus
end;
function "+"(L: STD_ULOGIC; R: SIGNED) return SIGNED is
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