timing simulation- output equal xx - Active HDL 7.1+ISE8.2

M

MariuszK

Hello,

I have:
Active HDL 7.1+sp2
-DesignFlowUpdatefor7[1].1sp2.exe
-XilinxSchematicLibrariesISE8[1].2sp2forActive-HDL7.1(..).exe
-XilinxVHDLLibrariesISE8[1].2SP2withIPUpdate1forActiv(..).exe

ISE 8.2+sp2

Why, in timing simulation output signals always equal XX?
Synthesis and implementation without warnings (errors). Simulation
after synthesis work correctly.

Should I install any additional packages?
Should be used global reset?

Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
 
C

charles.elias

MariuszK said:
Hello,

I have:
Active HDL 7.1+sp2
-DesignFlowUpdatefor7[1].1sp2.exe
-XilinxSchematicLibrariesISE8[1].2sp2forActive-HDL7.1(..).exe
-XilinxVHDLLibrariesISE8[1].2SP2withIPUpdate1forActiv(..).exe

ISE 8.2+sp2

Why, in timing simulation output signals always equal XX?
Synthesis and implementation without warnings (errors). Simulation
after synthesis work correctly.

Should I install any additional packages?
Should be used global reset?

Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
Click to expand...

Your problem is that you are trying to add 2 std_logic_vectors. Try
this:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;


entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;


--}} End of automatically maintained section


architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
variable sum : unsigned;
begin
sum := TO_UNSIGNED( in1 ) + TO_UNSIGNED( in2 );
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= std_logic_vector( sum );
end if;
end process;
end MyTestSimple;
 
C

charles.elias

MariuszK said:
Hello,

I have:
Active HDL 7.1+sp2
-DesignFlowUpdatefor7[1].1sp2.exe
-XilinxSchematicLibrariesISE8[1].2sp2forActive-HDL7.1(..).exe
-XilinxVHDLLibrariesISE8[1].2SP2withIPUpdate1forActiv(..).exe

ISE 8.2+sp2

Why, in timing simulation output signals always equal XX?
Synthesis and implementation without warnings (errors). Simulation
after synthesis work correctly.

Should I install any additional packages?
Should be used global reset?

Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
Click to expand...

I think I made an error in my first reply. If the addition statement
is not inside the clocking statement then I think in1 and in2 should be
in the sensitivity list.

Charles
 
C

charles.elias

MariuszK said:
Hello,

I have:
Active HDL 7.1+sp2
-DesignFlowUpdatefor7[1].1sp2.exe
-XilinxSchematicLibrariesISE8[1].2sp2forActive-HDL7.1(..).exe
-XilinxVHDLLibrariesISE8[1].2SP2withIPUpdate1forActiv(..).exe

ISE 8.2+sp2

Why, in timing simulation output signals always equal XX?
Synthesis and implementation without warnings (errors). Simulation
after synthesis work correctly.

Should I install any additional packages?
Should be used global reset?

Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
Click to expand...

Your problem is that you are trying to add 2 std_logic_vectors. Try
this:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;


entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;


--}} End of automatically maintained section


architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
variable sum : unsigned;
begin
sum := TO_UNSIGNED( in1 ) + TO_UNSIGNED( in2 );
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= std_logic_vector( sum );
end if;
end process;
end MyTestSimple;
Click to expand...

I am not doing too well as an advisor today. Another error in my reply
is that I didn't dimension the unsigned variable sum. It should have
the same range as out1.
 
C

charles.elias

MariuszK said:
Hello,

I have:
Active HDL 7.1+sp2
-DesignFlowUpdatefor7[1].1sp2.exe
-XilinxSchematicLibrariesISE8[1].2sp2forActive-HDL7.1(..).exe
-XilinxVHDLLibrariesISE8[1].2SP2withIPUpdate1forActiv(..).exe

ISE 8.2+sp2

Why, in timing simulation output signals always equal XX?
Synthesis and implementation without warnings (errors). Simulation
after synthesis work correctly.

Should I install any additional packages?
Should be used global reset?

Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
Click to expand...

Your problem is that you are trying to add 2 std_logic_vectors. Try
this:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;


entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;


--}} End of automatically maintained section


architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
variable sum : unsigned;
begin
sum := TO_UNSIGNED( in1 ) + TO_UNSIGNED( in2 );
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= std_logic_vector( sum );
end if;
end process;
end MyTestSimple;
Click to expand...

I am not doing too well as an advisor today. Another error in my reply
is that I didn't dimension the unsigned variable sum. It should have
the same range as out1.
 
M

MariuszK

I think I made an error in my first reply. If the addition statement
is not inside the clocking statement then I think in1 and in2 should be
in the sensitivity list.

Charles
Click to expand...

I added in1 and in2 to sensitivity list of process. Result:eek:utput
signal still equal XX. Any other ideas?
 
K

KJ

MariuszK said:
Problem is global (independent of module, entity, used family-Virtex1-4
). Below the simplest example, where this error occur:

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;

entity MyTestSimple is
port(
CLK : in STD_LOGIC;
in1 : in STD_LOGIC_VECTOR(7 downto 0);
in2 : in STD_LOGIC_VECTOR(7 downto 0);
out1 : out STD_LOGIC_VECTOR(7 downto 0)
);
end MyTestSimple;

--}} End of automatically maintained section

architecture MyTestSimple of MyTestSimple is
begin
process(CLK)
begin
if CLK'event and CLK='1' then
-- enter your statements here --
out1 <= in1 + in2;
end if;
end process;
end MyTestSimple;

Best Regards
Mariusz
Click to expand...

As an aside, you should use ieee.numeric_std package when you do any
sort of math it is a standard whereas "IEEE.STD_LOGIC_UNSIGNED" is not.

But that's not the problem, and looking at your code one can not
determine the problem so here are some areas to look at. First, in
your simulator, navigate down to the 'MyTestSimple' entity and add CLK,
in1, in2 and out1 to your wave window.
- Is Clk running?
- Are in1 and in2 what you expect them to be?
- Are you waiting long enough after the rising edge of Clk for 'out1'
to be valid? This number comes out of the timing report from your
build. If it says 5ns, then don't complain that 'out' is wrong 1ps
after the rising edge.

If both of the above look OK but out1 is 'XX' then the problem is that
there is something else driving 'out1'. This would have to be in some
code other that which you posted. To find it, you need to use the
simulator to see what other sources are driving this signal. Maybe
something in your testbench?

You might also want to consider changing to 'std_ulogic_vector' instead
of 'std_logic_vector'. The difference between std_ulogic and std_logic
is that it is not legal to have two drivers on any signal declared to
be type 'std_ulogic' (but this is permissable with std_logic). If you
do try to drive a std_ulogic in two places you'll either get a compiler
error straight off or when you go to start the simulation you'll get
the complaint and it will generally point to the offending
parties...one of which must be wrong.

Good luck.

KJ
 

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