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Design Verification VHDL ET062G & ET063G Lecture 5 Najeem Lawal 2012

Design Verification VHDL ET062G & ET063G Lecture 5 Najeem Lawal 2012. Design Verification. Outline Test Bench Clock generation Reading BMP Generating Control Signal Testing the result. Error Management in VHDL. Assert statement Syntax: Assert <condition> Report <message>

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Design Verification VHDL ET062G & ET063G Lecture 5 Najeem Lawal 2012

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  1. Design Verification VHDL ET062G & ET063G Lecture 5 Najeem Lawal 2012

  2. Design Verification • Outline • Test Bench • Clock generation • Reading BMP • Generating Control Signal • Testing the result VHDL ET062G & ET063G Lecture 5

  3. Error Management in VHDL Assert statement Syntax: Assert <condition> Report <message> Severity <error_level> ; Message and Error Level are displayed in the simulator console as text. Assert statements can be both sequential and concurrent statements. Assert statements should only be in the test-benches because there are not synthesizable. VHDL ET062G & ET063G Lecture 5

  4. Error Management in VHDL architecture ex of assert_ex is begin assert a /= '1' or b /= '1' report “a='1' and b='1' at the same time!” severity Warning; P1 : process(a,b)‏ begin if a ='1' and b = '1' then assert false report “a='1' and b='1'”; end if end process P1; end architecture ex; Entity assert_ex is port ( a,b : in std_logic; q : out std_logic); end entity assert_ex; architecture ex of assert_ex is VHDL ET062G & ET063G Lecture 5

  5. TESTBENCHES in VHDL • AT least 3 essentialcomponents • Unit Under Test UUT • Stimuli generator • Response tester VHDL ET062G & ET063G Lecture 5

  6. TESTBENCHES in VHDL • AT least 3 essentialcomponents • Unit Under Test UUT • Your designs • 4 bit adder • Counter • Sliding window • Range sensor • Edge detector • Complete project • Stimuli generator • Response tester VHDL ET062G & ET063G Lecture 5

  7. TESTBENCHES in VHDL • AT least 3 essentialcomponents • Unit Under Test UUT • Stimuli generator • Many specialised stimuli generator • Clocks, reset • Control signals • Data signals • Models of sensors and actuator your UUT connects to • Response tester VHDL ET062G & ET063G Lecture 5

  8. TESTBENCHES in VHDL • AT least 3 essentialcomponents • Unit Under Test UUT • Stimuli generator • Response tester • Many specialised test modules • Truth table • Established values or controls status • Waveform analysis VHDL ET062G & ET063G Lecture 5

  9. Typical testbench • LIBRARY ieee; • USE ieee.std_logic_1164.ALL; • USE ieee.std_logic_unsigned.all; • USE ieee.numeric_std.ALL; • ENTITY test_Project_2010 IS • -- nothing here • -- no ports • -- this is the envelop of the universe • END entity test_Project_2010; Closed entity - no port It is the highest module VHDL ET062G & ET063G Lecture 5

  10. example • ARCHITECTURE behavior OF test_Project_2010 IS • -- ComponentDeclaration for the Unit Under Test (UUT) • COMPONENT edge_sobel_wrapper • PORT( • clk : IN std_logic; • fsync_in : IN std_logic; • rsync_in : IN std_logic; • pdata_in : IN std_logic_vector(7 downto 0); • fsync_out : OUT std_logic; • rsync_out : OUT std_logic; • pdata_out : OUT std_logic_vector(7 downto 0) • ); • END COMPONENT; • SIGNAL clk : std_logic := '0'; • SIGNAL fsync_in : std_logic := '0'; • SIGNAL rsync_in : std_logic := '0'; • SIGNAL pdata_in : std_logic_vector(7 downto 0) := (others=>'0'); • ….. VHDL ET062G & ET063G Lecture 5

  11. example To perform some asynchronous functions • BEGIN • -- Instantiate the Unit Under Test (UUT) • uut: edge_sobel_wrapper PORT MAP( • clk => clk, • fsync_in => fsync_in, • rsync_in => rsync_in, • pdata_in => pdata_in, • fsync_out => fsync_out, • rsync_out => rsync_out, • pdata_out => pdata_out • ); Similar clock as UUT img_read : entitywork.img_testbench port map ( pclk_i => clk, reset_i => reset, fsync_i => fsync_out, rsync_i => rsync_out, pdata_i => pdata_out, cols_o => open, rows_o => open, col_o => open, row_o => open, fsync_o => fsync_in, rsync_o => rsync_in, pdata_o => pdata_in); Mimics a camera Input clock, data & controls And output It’s good to have naming convention Mimics a monitor VHDL ET062G & ET063G Lecture 5

  12. example Clock is just a signal that toggles between ‘0’ and ‘1’ at a predefined rate. • clock_generate: process (clk) • constantT_pw : time := 50 ns; -- Clock period is 100ns. • begin -- process img • ifclk = '0' then • clk <= '1' after T_pw, '0' after 2*T_pw; • endif; • end process clock_generate; • reset <= '1', '0' after 60 ns; • END; 10 MHz clock. Because the camera is 10 MHz 50 % duty Default value of clock is ‘0’ Time long enough to do a few house cleaning and data initialization VHDL ET062G & ET063G Lecture 5

  13. hints • The UUT IS SELF SUFFICIENT AND SYNTHESISABLE • IT CONNECTS TO OTHER DEVICES THROUGH THE FPGA IO PINS • CONTAINTS ALL PORTS AND GENERICS FOR IMPLEMENTATION • CLOCKS SHOULD BE CLOSE TO FINAL IMPLEMENTATION TIMING REQUIREMENTS • YES, WE NEED RESET TO KICK START US FROM OR BRING US TO KNOW STATES VHDL ET062G & ET063G Lecture 5

  14. img_testbench • library ieee; • use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use ieee.std_logic_unsigned.all; • use std.textio.all; • entity img_testbench is • port ( • pclk_i : in std_logic; • reset_i : in std_logic; • fsync_i : in std_logic; • rsync_i : in std_logic; • pdata_i : in std_logic_vector(7 downto 0); • cols_o : out std_logic_vector(15 downto 0); • rows_o : out std_logic_vector(15 downto 0); • col_o : out std_logic_vector(15 downto 0); • row_o : out std_logic_vector(15 downto 0); • rsync_o : out std_logic; • fsync_o : out std_logic; • pdata_o : out std_logic_vector(7 downto 0) ); • end img_testbench; VHDL ET062G & ET063G Lecture 5

  15. img_testbench How to read image files a stream of 8 bit • ... • architecture main of img_testbench is • type ByteT is (c0,c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12,c13,c14,c15,c16,c17,c18, • c19,c20,c21,c22,c23,c24,c25,c26,c27,c28,c29,c30,c31,c32,c33,c34, • --- • subtype Byte is ByteT; • typeByteFileType is file of Byte; • fileinfile : ByteFileTypeopenread_mode is "test.bmp"; • fileoutfile : ByteFileTypeopenwrite_mode is "result_08bits.bmp"; • … A new type that can read 8-bit character from file. VHDL ET062G & ET063G Lecture 5

  16. img_testbench • ... • -- integer to bit_vector conversion • function int2bit_vec(A: integer; SIZE: integer) return BIT_VECTOR is • variable RESULT : BIT_VECTOR(SIZE-1 DOWNTO 0); • variable TMP : integer; • begin • TMP := A; • for i in 0 to SIZE - 1 loop • if TMP mod 2 = 1 then RESULT(i) := '1'; • else RESULT(i) := '0'; • end if; • TMP := TMP / 2; • end loop; • return RESULT; • end; • … A function that converts integers to bits vector of a given size. Subprograms in VHDL - procedure? - function? VHDL ET062G & ET063G Lecture 5

  17. img_testbench Store RGB pixel values • ... • begin -- main • img_read : process (pclk_i) • variable pixelB : Byte; • variable pixelG : Byte; • variable pixelR : Byte; • variable pixel : Byte; • variable pixel1 : REAL; • variable cols : std_logic_vector(15 downto 0); • variable rows : std_logic_vector(15 downto 0); • variable col : std_logic_vector(15 downto 0); • variable row : std_logic_vector(15 downto 0); • variable cnt : integer; • variable rsync : std_logic := '0'; • variable stop : std_logic; • begin -- process img_read • if (reset_i = '1') then • pdata_o <= (others => '0'); • col := (others => '0'); • row := (others => '0'); • … For reading from the BMP File Effective pixel value How many rows, columns which row and column are we in the image file Counter for blanking Valid pixel indicator When to stop VHDL ET062G & ET063G Lecture 5

  18. img_testbench • ... • for i in 0 to 53 loop -- read header infos • read(infile, pixel); • write(outfile, pixel); • case i is • when 18 => -- 1st byte of cols • cols(7 downto 0 ) := To_Stdlogicvector(int2bit_vec(ByteT'pos(pixel), 8)); • when 19 => -- 2nd byte of cols • cols(15 downto 8) := To_Stdlogicvector(int2bit_vec(ByteT'pos(pixel), 8)); • when 22 => -- 1st byte of rows • rows(7 downto 0 ) := To_Stdlogicvector(int2bit_vec(ByteT'pos(pixel), 8)); • when 23 => -- 2nd byte of rows • rows(15 downto 8) := to_Stdlogicvector(int2bit_vec(ByteT'pos(pixel), 8)); • when 24 => -- do important things • cols_o <= cols; • rows_o <= rows; • cols := cols - 1; • rows := rows - 1; • when others => • null; • end case; • end loop; -- i • … Assign output Assign upper limit of internal counters VHDL ET062G & ET063G Lecture 5

  19. Bmp file format VHDL ET062G & ET063G Lecture 5

  20. img_testbench • ... • rsync := '1'; • cnt := 10; • stop := '0'; • elsif (pclk_i'event and pclk_i = '1') then • rsync_o <= rsync; • if rsync = '1' then • if row = "0000000000000000" and col = "0000000000000000" then • fsync_o <= '1'; • else • fsync_o <= '0'; • end if; • … VHDL ET062G & ET063G Lecture 5

  21. img_testbench • ... • if stop = '0' then • read(infile, pixelB); -- B • read(infile, pixelG); -- G • read(infile, pixelR); -- R • pixel1 := (ByteT'pos(pixelB)*0.11) + (ByteT'pos(pixelR)*0.3) + (ByteT'pos(pixelG)*0.59); • pdata_o <= CONV_STD_LOGIC_VECTOR(INTEGER(pixel1), 8); • col_o <= col; • row_o <= row; • end if; • … VHDL ET062G & ET063G Lecture 5

  22. img_testbench • ... • if col = cols then • col := (others => '0'); • rsync := '0'; • if row = rows then • File_Close(infile); • stop := '1'; • else • row := row + 1; • end if; -- row • else • col := col + 1; • end if; -- col • … Where are we in the image 640 clk 640 clk 10 clk rsync = ‘1’ rsync = ‘1’ rsync = ‘0’ VHDL ET062G & ET063G Lecture 5

  23. img_testbench • ... • else -- rsync • if cnt > 0 then • cnt := cnt -1; • else • cnt := 10; • rsync := '1'; • end if; • pdata_o <= (others => 'X'); • end if; -- rsync • … VHDL ET062G & ET063G Lecture 5

  24. img_testbench • ... • if rsync_i = '1' then • write(outfile, ByteT'val(ieee.numeric_std.To_Integer(ieee.numeric_std.unsigned(pdata_i)))); --, pixel); • write(outfile, ByteT'val(ieee.numeric_std.To_Integer(ieee.numeric_std.unsigned(pdata_i)))); --, pixel); • write(outfile, ByteT'val(ieee.numeric_std.To_Integer(ieee.numeric_std.unsigned(pdata_i)))); --, pixel); • end if; -- rsync_i • end if; -- clk • end process img_read; • end main; • … VHDL ET062G & ET063G Lecture 5

  25. Range sensor • Srf05 http://www.robotstorehk.com/sensors/doc/srf05tech.pdf • 10us pulse to the Trigger input • 50ms period between each Trigger pulse • Mode 1 recommended VHDL ET062G & ET063G

  26. PROJECT IMPLEMENTATION • Controller is FPGA • System Clock and Exposure are generated • Understand timing diagrams and implement the project. VHDL ET062G & ET063G

  27. Sliding window • An image is read from left to right and top to bottom • sliding • Given an algorithm with many tasks O(x,y) = F(x,y) x I(x,y) • Some of the task are neighbourhood oriented • sliding window • N x M sliding window. • N and M are odd numbers VHDL ET062G & ET063G

  28. Sliding window • Suggested implementation architecture • linebuffers • Boundary controller • Pixel switch • Filter function • Output synchronisation VHDL ET062G & ET063G

  29. Sliding window • At the image edges • There are invalid pixel • How do you build a valid neighbouthood of pixels around edge pixels? • 3 alternatives • Avoid processing edge pixels • Copy centre pixel to the invalid pixel locations • Reflections. Default to 0 or 255 VHDL ET062G & ET063G

  30. questions • About FPGA / VHDL • ABOUT VGA DISPLAY / timing • ABOUT IMAGE SENSOR timing • ABOUT RANGE SENSOR • About line buffers • About memories & counters VHDL ET062G & ET063G Lecture 5

  31. End of lecture 5 Outline • Test Bench • Clock generation • Reading BMP • Generating Control Signal • Testing the result VHDL ET062G & ET063G Lecture 5

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