VHDL code verification

[Lukáš Král]

Hello everybody , i am new to VHDL and i need somebody to verify that my code will work. It should draw 6 squares (different colors) on VESA 800x600 @72Hz monitor. Pix.clock is 50 MHz. Please ignore comments (they are in my native language). Squares should be 100x100px. I need to know if this code would work when i use it on Spartan 3E Starter board. If you need more information then tell me. Thanks all who are willing to help and sorry for my imperfect English.

CODE:

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity kral_roc_cit is
Port ( clk : in STD_LOGIC;
reset : in STD_LOGIC;
Red : out STD_LOGIC;
Green : out STD_LOGIC;
Blue : out STD_LOGIC;
hs : out STD_LOGIC;
vs : out STD_LOGIC);
end kral_roc_cit;

architecture Behavioral of kral_roc_cit is

signal count_pixel : STD_LOGIC_VECTOR (10 downto 0) := (others=>'0') ;
signal count_radek : STD_LOGIC_VECTOR (9 downto 0) := (others=>'0');
signal R : STD_LOGIC := '0';
signal G : STD_LOGIC := '0';
signal B : STD_LOGIC := '0';
signal h_sync : STD_LOGIC := '0';
signal v_sync : STD_LOGIC := '0';

constant h_active : integer := 800;
constant h_front_porch : integer := 56;
constant h_back_porch : integer := 64;
constant h_total : integer := 1040;

constant v_active : integer := 600;
constant v_front_porch : integer := 37;
constant v_back_porch : integer := 23;
constant v_total : integer := 666;

begin

-- PoÄítání pozice na řádku

process (clk)
begin
if reset = '1' then
count_pixel <= (others=>'0');
elsif clk'event and clk = '1' then
if count_pixel = (h_total - 1) then
count_pixel <= (others=>'0');
else
count_pixel <= count_pixel + 1;
end if;
end if;
end process;

-- Synchronizace řádku

process (clk)
begin
if reset = '1' then
h_sync <= '0';
elsif clk'event and clk = '1' then
if count_pixel = (h_active + h_front_porch -1) then
h_sync <= '1';
elsif count_pixel = (h_total - h_back_porch - 1) then
h_sync <= '0';
end if;
end if;
end process;

-- PoÄítání pozice v rámci

process (clk)
begin
if reset = '1' then
count_radek <= (others=>'0');
elsif clk'event and clk = '1' then
if ((count_radek = v_total - 1) and (count_pixel = h_total - 1)) then
count_radek <= (others=>'0');
elsif count_pixel = (h_total - 1) then
count_radek <= count_radek + 1;
end if;
end if;
end process;

-- Synchronizace rámců

process (clk)
begin
if reset = '1' then
v_sync <= '0';
elsif clk'event and clk = '1' then
if count_radek = (v_active + v_front_porch -1) and
count_pixel = (h_total - 1) then
v_sync <= '1';
elsif count_radek = (v_total - v_back_porch - 1) and
count_pixel = (h_total - 1) then
v_sync <= '0';
end if;
end if;
end process;

-- Barvení Ätverců

process (clk)
begin
if clk'event and clk = '1' then
-- Barvení Ätverce (1. - green - tÅ™etí řádek )
if (count_pixel >= "00010011011" ) -- 100 + h_front_porch -1 (155)
and (count_pixel <= "00011111111" ) -- 200 + h_front_porch -1 (255)
and (count_radek >= "0101100100" ) -- 320 + v_front_porch -1 (356)
and (count_radek <= "0111001000" ) -- 420 + v_front_porch -1 (456)
then
G <= '1';
-- Barvení Ätverce (2. - yellow - první řádek)
elsif (count_pixel >= "00011111111" ) -- 200 + h_front_porch -1 (255)
and (count_pixel <= "00101100011" ) -- 300 + h_front_porch -1 (355)
and (count_radek >= "0001001100" ) -- 40 + v_front_porch -1 (76)
and (count_radek <= "0010110000" ) -- 140 + v_front_porch -1 (176)
then
R <= '1';
G <= '1';
-- Barvení Ätverce (3. - white - druhý řádek)
elsif (count_pixel >= "00101100011" ) -- 300 + h_front_porch -1 (355)
and (count_pixel <= "00111000111" ) -- 400 + h_front_porch -1 (455)
and (count_radek >= "0011011000" ) -- 180 + v_front_porch -1 (216)
and (count_radek <= "0100111100" ) -- 280 + v_front_porch -1 (316)
then
R <= '1';
G <= '1';
B <= '1';
-- Barvení Ätverce (4. - cyan - první řádek)
elsif (count_pixel >= "00111000111" ) -- 400 + h_front_porch -1 (455)
and (count_pixel <= "01000101011" ) -- 500 + h_front_porch -1 (555)
and (count_radek >= "0001001100" ) -- 40 + v_front_porch -1 (76)
and (count_radek <= "0010110000" ) -- 140 + v_front_porch -1 (176)
then
G <= '1';
B <= '1';
-- Barvení Ätverce (5. - white - Ätvrtý řádek)
elsif (count_pixel >= "01000101011" ) -- 500 + h_front_porch -1 (555)
and (count_pixel <= "01010001111" ) -- 600 + h_front_porch -1 (655)
and (count_radek >= "0111110000" ) -- 460 + v_front_porch -1 (496)
and (count_radek <= "1001010100" ) -- 560 + v_front_porch -1 (596)
then
G <= '1';
B <= '1';
R <= '1';
-- Barvení Ätverce (6. - green - druhý řádek)
elsif (count_pixel >= "01010001111" ) -- 600 + h_front_porch -1 (655)
and (count_pixel <= "01011110011" ) -- 700 + h_front_porch -1 (755)
and (count_radek >= "0011011000" ) -- 180 + v_front_porch -1 (216)
and (count_radek <= "0100111100" ) -- 280 + v_front_porch -1 (316)
then
G <= '1';
else
G <= '0';
B <= '0';
R <= '0';
end if;
end if;
end process;

-- Připojení výstupů

Red <= R ;
Green <= G ;
Blue <= B ;
hs <= h_sync ;
vs <= v_sync ;


end Behavioral;

 

[KJ]

You didn't post the code for your testbench. I'm guessing that is because you didn't write one in which case here is the formula to determine if your design works:

1. Write a testbench that provides stimulus
2. Verify either in the testbench itself using assertions or in the waveform window that everything is how you expect it.
3. Modify design and/or testbench code to fix all errors. Return to step 1. If no errors are found and you believe the testbench sufficiently exercises the design to produce the desired result proceed to step 4.
4. Verify timing
5. Test in hardware.

Kevin Jennings

 

[KJ]

and sorry for my imperfect English.

By the way, your English is very good!

Kevin Jennings

 

[Lukáš Král]

Already simulated with waveform testbench (since i do not know how to writeregular testbench). All seems to be in order. I just want to make sure that this code can draw squares on monitor before i hand over my work. Never worked with monitors before so i do not know if it does everything i need.

Kevin Jennings thanks for response. (I am glad that my english is not that bad .)

 

[rickman]

Already simulated with waveform testbench (since i do not know how to write regular testbench). All seems to be in order. I just want to make sure that this code can draw squares on monitor before i hand over my work. Never worked with monitors before so i do not know if it does everything i need.

Kevin Jennings thanks for response. (I am glad that my english is not that bad .)

Why don't you try writing a test bench? If you have time it would be a
great learning experience. Plenty of people here to offer help.

 

[Lukáš Král]

Dne úterý, 12. března 2013 21:16:51 UTC+1 rickman napsal(a):

Why don't you try writing a test bench? If you have time it would be a

great learning experience. Plenty of people here to offer help.



--



Rick

That is actually great idea. I will look at it and try something.

 

[rickman]

Dne úterý, 12. března 2013 21:16:51 UTC+1 rickman napsal(a):

That is actually great idea. I will look at it and try something.

If you nose around your tool, you may find a command to generate
boilerplate for a testbench for your module. Most commercial tools have
that these days. It saves a bit of typing for the module declaration
and port map.

 

[Andy]

FYI, Since the -93 version of the language, you can avoid the uut component declaration by instantiating the UUT directly as an entity:

uut: ENTITY work.my_entity(my_entity_architecture)

The "ENTITY" keyword is required (to distinguish this from a component instantiation.)

The "(my_entity_architecture)" part is optional for specifying the UUT architecture.

Note that with direct entity instantiation, the entity must be compiled before the testbench architecture is compiled.

If the architecture of the uut entity is specified, it must also be compiled before the testbench architecture.

Andy

 

[Allan Herriman]

FYI, Since the -93 version of the language, you can avoid the uut
component declaration by instantiating the UUT directly as an entity:

uut: ENTITY work.my_entity(my_entity_architecture)

The "ENTITY" keyword is required (to distinguish this from a component
instantiation.)

The "(my_entity_architecture)" part is optional for specifying the UUT
architecture.

Note that with direct entity instantiation, the entity must be compiled
before the testbench architecture is compiled.

If the architecture of the uut entity is specified, it must also be
compiled before the testbench architecture.

I was recently pleased to discover that the tools I use (Modelsim, XST
and Quartus) all support direct entity instantiation of Verilog modules
in VHDL architectures.

Finally I get to say goodbye to component declarations. I switched to
direct entity instatiation for most of my code about 12 years ago, and
until recently "Verilog in VHDL" was the only reason I still had to
declare components.

We seem to have a lot of mixed language projects here for some reason.

Regards,
Allan