HI.
I written traffic signal program .Ran on ghdl simulator gtk wave not displaying waveform/
commands used :ghdl -a tra.vhd
ghdl -e tra
ghdl -r tra --vcd=ha.vcd=$--stop-time=100ns
gtkwave tra.vcd
library ieee;
use ieee.std_logic_1164.all;
entity tra is
port(rst,clk : in std_logic;
q : out std_logic_vector(2 downto 0));
end;
architecture fsm of tra is
type state_type is(red,green,yellow);
signal ps,ns1 : state_type;
begin
process(clk,rst)
begin
if(rst = '0')then
ps <= red;
elsif clk'event and clk='1'then
ps <= ns1;
end if;
end process;
process(ps,ns1)
begin
case ps is
when red =>
q <="001";
ns1<= green;
when green =>
q <= "010";
ns1 <= yellow;
when yellow =>
q <= "100";
ns1 <= red;
end case;
end process;
end fsm;
Thanks in advanvce
Regards
Raghavendra
