library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.numeric_std.all;
entity counter_tb is
end counter_tb;
architecture Behavioral of counter_tb is
component sim_counter
port(clk, reset : in std_logic;
count : out std_logic_vector(3 downto 0)
);
end component;
signal clk : std_logic := '0';
signal reset : std_logic := '0';
signal count : std_logic_vector(3 downto 0);
constant clk_period : time := 20ns;
begin
dut : sim_counter port map(clk => clk, reset => reset, count => count);
clk <= '1' after 30ns when clk = '0' else
'0' after 20ns;
reset <= '1' after 5ns;
reset <= '0' after 5ns;
end Behavioral;
在编译后出现警告说以下几行 (Vcom-1207) An abstrct literal and an identifier must have a separator between them.
clk <= '1' after 30ns when clk = '0' else
'0' after 20ns;
reset <= '1' after 5ns;
reset <= '0' after 5ns;
请高手指教该如何解决？？？
谢谢
