加减与有符号和无符号库
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity mult_test is
port(sclk : in std_logic ;
a : in std_logic_vector(3 downto 0);
b : in std_logic_vector(3 downto 0);
c : out std_logic_vector(7 downto 0)
);
end mult_test;
architecture rtl of mult_test is
begin
process(sclk)
begin
if sclk'event and sclk = '1' then
c <= a * b;
end if;
end process;
end rtl;
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_signed.all;
entity mult_test is
port(sclk : in std_logic ;
a : in std_logic_vector(3 downto 0);
b : in std_logic_vector(3 downto 0);
c : out std_logic_vector(7 downto 0)
);
end mult_test;
architecture rtl of mult_test is
begin
process(sclk)
begin
if sclk'event and sclk = '1' then
c <= a * b;
end if;
end process;
end rtl;
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity mult_test1 is
port(sclk : in std_logic ;
a : in std_logic_vector(3 downto 0);
b : in std_logic_vector(3 downto 0);
d : out std_logic_vector(3 downto 0)
);
end mult_test1;
architecture rtl of mult_test1 is
begin
process(sclk)
begin
if sclk'event and sclk = '1' then
d <= a + b;
end if;
end process;
end rtl;
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_signed.all;
entity mult_test1 is
port(sclk : in std_logic ;
a : in std_logic_vector(3 downto 0);
b : in std_logic_vector(3 downto 0);
d : out std_logic_vector(3 downto 0)
);
end mult_test1;
architecture rtl of mult_test1 is
begin
process(sclk)
begin
if sclk'event and sclk = '1' then
d <= a + b;
end if;
end process;
end rtl;
