I'm trying to simulate a pulse width modulate (PMW) waveform generator and getting a syntax error in ISE. Checked fuse.xmsgs and found out it's near counter. Can someone point out the syntax error, please?
library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.numeric_std.all;
entity pwm_gen is
port
(
clock, reset : in std_logic;
width : in std_logic_vector(7 downto 0);
pwm : out std_logic);
end pwm_gen;
architecture bhv of pwm_gen is
type counter is range 0 to 255;
counter count := 0;
begin
process (clock)
begin
if (reset = '1') then
count <= 0;
elsif (clock'event and clock = '1') then
if (count <= width) then
count <= count + 1;
pwm <= '1';
else
count <= count + 1;
pwm <= '0';
end if;
end if;
end process;
end bhv;
counter count := 0;
This is illegal syntax, as you didnt declare the object class (signal, constant, variable). You need to use the format:
signal count : counter := 0
This is also illegal, as you are comparing an integer to a std_logic_vector
that you havent included a package for. You need to convert the slv to an unsigned
if (count <= unsigned(width)) then
And finally, reset
is missing from the sensitivity list