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Old 10-07-2006, 03:44 PM
rob
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Default VHDL count error when cascading

I am using 3 * gal22v20's cant change them.
Clocks are all wired together and ripple out is connected to the enable
of the next chip. After compiling the code the MSD decoder does not
count correctly and appears to be taking 9/10 clk pluses to the enable
causing it to run the fast on the 3rd chip. here is the original code
there are no PCB error. Below that is a remodelled VHDL that is giving
errors. Can anyone give me some insighty into this error.
Thanks
Rob

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity segment_cnt is

port(

clk,mr,en,pause, clk_in :in std_logic;
segs :buffer std_logic_vector(6 downto 0);
clk_out ut std_logic;
rco : out std_logic
);

end segment_cnt;

architecture behav of segment_cnt is
begin

cnt_procrocess(clk, mr)
begin
if(mr='0') then segs <= "0000001";
elsif(clk'event and clk ='1') then
if (pause = '0') then segs <= segs;
elsif(en = '0' and pause = '1') then case segs is
when "0000001" => -- 0 goto 1
segs<="1001111";

when "1001111" => -- 1 goto 2
segs<="0010010";

when "0010010" => -- 2 goto 3
segs<="0000110";

when "0000110"=> -- 3 goto 4
segs<="1001100";

when "1001100" => -- 4 goto 5
segs<="0100100";

when "0100100" => -- 5 goto 6
segs<="0100000";

when "0100000" => -- 6 goto 7
segs<="0001111";

when "0000111" => -- 7 goto 8
segs<="0000000";

when "0000000" => -- 8 goto 9
segs<="0001100";

when others => -- 9 goto 0
segs<="0000001";

end case;
end if;
end if;
end process cnt_proc;
clk_out <= clk_in;
rco <= '1'when (segs = "0001100" and en ='0')else '0';
end behav;

I have tried to add a loop in the VHDL to loop 10 time before the count
starts
here is that code and the error that it produced.

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity segment_cnt is

port(

clk,mr,en,pause, clk_in :in std_logic;
segs :buffer std_logic_vector(6 downto 0);
count :buffer std_logic_vector(3 downto 0);
clk_out ut std_logic;
rco : out std_logic
);

end segment_cnt;

architecture behav of segment_cnt is
begin

cnt_procrocess(clk, mr)
begin
if(mr='0') then segs <= "0000001";
elsif(clk'event and clk ='1') then
if (pause = '0') then segs <= segs;
elsif(en = '0' and pause = '1') then

count <= count +1;
if (count ="1001") then
count <= "0000";
else count <= "0000";
end if;
end if;
if(count = "1001" and pause = '1') then case segs is
when "0000001" => -- 0 goto 1
segs<="1001111";

when "1001111" => -- 1 goto 2
segs<="0010010";

when "0010010" => -- 2 goto 3
segs<="0000110";

when "0000110"=> -- 3 goto 4
segs<="1001100";

when "1001100" => -- 4 goto 5
segs<="0100100";

when "0100100" => -- 5 goto 6
segs<="0100000";

when "0100000" => -- 6 goto 7
segs<="0001111";

when "0000111" => -- 7 goto 8
segs<="0000000";

when "0000000" => -- 8 goto 9
segs<="0001100";

when others => -- 9 goto 0
segs<="0000001";

end case;
end if;end if;
end process cnt_proc;
clk_out <= clk_in;
rco <= '1'when (segs = "0001100" and en ='0')else '0';
end behav;

Design optimization (dsgnopt)
Device fitting (pla2jed)
Error: Logic equation for signal count(3).AR is redefining a banked
expression.
Error: Logic equation for signal count(2).AR is redefining a banked
expression.
Error: Logic equation for signal count(1).AR is redefining a banked
expression.
Error: Logic equation for signal count(0).AR is redefining a banked
expression.

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