VHDL程序设计题.doc
VHDL程序设计题四、 编程题(共50分)1、请补全以下二选一VHDL程序(本题10分)Entity mux isport(d0,d1,sel:in bit;q:out BIT ); (2)end mux;architecture connect of MUX is (4) signal tmp1, TMP2 ,tmp3:bit; (6)begin cale:block begin tmp1<=d0 and sel; tmp2<=d1 and (not sel) tmp3<= tmp1 and tmp2;q <= tmp3; (8) end block cale; end CONNECT ; (10)2、编写一个2输入与门的VHDL程序,请写出库、程序包、实体、构造体相关语句,将端口定义为标准逻辑型数据结构(本题10分)&abyLIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; (2) ENTITY nand2 IS PORT (a,b:IN STD_LOGIC; (4) y:OUT STD_LOGIC); (6) END nand2; ARCHITECTURE nand2_1 OF nand2 IS (8) BEGIN y <= a NAND b; -与y <=NOT( a AND b);等价 (10) END nand2_1;3、根据下表填写完成一个3-8线译码器的VHDL程序(16分)。LIBRARY IEEE;USE IEEE.STD_LOGIC_1164.ALL;ENTITY decoder_3_to_8 IS PORT (a,b,c,g1,g2a,g2b:IN STD_LOGIC; y:OUT STD_LOGIC_VECTOR(7 DOWNTO 0); (2)END decoder_3_to_8;ARCHITECTURE rtl OF decoder_3_to_8 IS SIGNAL indata:STD_LOGIC_VECTOR (2 DOWNTO 0);(4)BEGIN indata <= c & b & a;(6)PROCESS (indata,g1,g2a,g2b) BEGIN IF (g1 = '1' AND g2a = '0' AND g2b = '0' ) THEN (8) CASE indata IS WHEN "000"=> y <= "11111110" WHEN "001" => y <= "11111101" WHEN "010" => y <= "11111011"(10) WHEN "011" => y <= "11110111" WHEN "100" => y <= "11101111" WHEN "101" => y <= "11011111" WHEN "110" => y <= "10111111" (12) WHEN "111" => y <= "01111111" WHEN OTHERS=> y <= "XXXXXXXX" END CASE; ELSE y <= "11111111"(14) END IF; END PROCESS;(16)END rtl; 4、三态门电原理图如右图所示,真值表如左图所示,请完成其VHDL程序构造体部分。(本题14分)LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL;ENTITY tri_gate ISPORT(din,en:IN STD_LOGIC; dout : OUT STD_LOGIC);END tri_gate ;ARCHITECTURE zas OF tri_gate ISBEGIN PROCESS (din,en) BEGINIF (en=1') THEN dout <= din;ELSE dout <= Z; END IF; END PROCESS ;END zas ;四、 编程题(共50分)1、根据一下四选一程序的结构体部分,完成实体程序部分(本题8分)entity MUX4 is port( (2)s:in std_logic_vector(1 downto 0); (4)d:in std_logic_vector(3 downto 0); (6)y:out std_logic (8); end MUX4; architecture behave of MUX4 isbeginprocess(s)beginif (s="00") theny<=d(0); elsif (s="01") theny<=d(1); elsif (s="10") theny<=d(2); elsif (s="11") theny<=d(3); elsenull; end if;end process;end behave; 2、编写一个数值比较器VHDL程序的进程(不必写整个结构框架),要求使能信号g低电平时比较器开始工作,输入信号p = q,输出equ为0,否则为1。(本题10分)process(p,q)(2)beginif g='0' then(4)if p = q thenequ <= '0' (6)else equ <= '1' (8)end if;else equ <= '1' (10)end if;end process;3、填写完成一个8-3线编码器的VHDL程序(16分)。Library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity eight_tri is port(b:in std_logic_vector(7 downto 0); (2)en:in std_logic;y:outstd_logic_vector(2 downto 0) (4));end eight_tri;architecture a of eight_tri is (6)signal sel: std_logic_vector(8 downto 0);beginsel<=en & b; (8)y<= “000” when (sel=”100000001”)else“001” when (sel=”100000010”)else (10)“010” when (sel=”100000100”)else“011” when (sel=”100001000”)else“100” when (sel=”100010000”)else (12) “101” when (sel=”100100000”)else“110” when (sel=”101000000”)else (14)“111” when (sel=”110000000”)else (16)“zzz”;end a;4、图中给出了4位逐位进位全加器,请完成其VHDL程序。(本题16分)library IEEE;use IEEE.std_logic_1164.all;use IEEE.std_logic_arith.all;use IEEE.std_logic_unsigned.all;entity full_add isport (a,b: instd_logic_vector (3 downto 0); (2)carr: inout std_logic_vector (4 downto 0);sum: outstd_logic_vector (3 downto 0);end full_add;architecture full_add_arch of full_add iscomponent adder (4)port (a,b,c:instd_logic;carr: inoutstd_logic;sum: out std_logic (6));end component;begincarr(0)<='0'u0:adder port map(a(0),b(0),carr(0),carr(1),sum(0);u1:adder port map(a(1),b(1),carr(1),carr(2),sum(1); (8)(10)u2:adder port map(a(2),b(2),carr(2),carr(3),sum(2); (12)u3:adder port map(a(3),b(3),carr(3),carr(4),sum(3); (14)(16)end full_add_arch;四、 编程(共50分)1、完成下图所示的触发器。(本题10分)CLRCLKDQQNlibrary IEEE;use IEEE.std_logic_1164.all;entity VposDff is port (CLK, CLR, D: in STD_LOGIC; -2分 Q, QN: out STD_LOGIC ); -4分end VposDff;architecture VposDff_arch of VposDff isbegin process ( CLK, CLR ) -6分 begin if CLR='1' then Q <= '0' QN <='1' elsif CLK'event and CLK='1' then Q <= D; QN <= not D; -8分 end if; end process; -10分end VposDff_arch; 2、完成以下4位全加器代码(本题10分)library IEEE;use IEEE.std_logic_1164.all;entity full_add isport (a,b: instd_logic_vector (3 downto 0);cin: instd_logic;cout: out std_logic;sum: outstd_logic_vector (3 downto 0);end full_add;architecture full_add_arch of full_add iscomponent adderport (a,b,c:instd_logic;carr: outstd_logic;sum: out std_logic);end component;signal c1,c2,c3: std_logic; 2分beginu0:adder port map(a(0),b(0),cin,c1,sum(0); 4分u1:adder port map(a(1),b(1),c1,c2,sum(1); 5分u2:adder port map(a(2),b(2),c2,c3,sum(2); 6分u3:adder port map(a(3),b(3),c3,cout,sum(3); 10分end full_add_arch;3、补充完整如下代码,使之完成4状态不断循环。(本题10分)ARCHITECTURE arc OF ss IStype states is ( st0,st1,st2,st3 ); 2分signal outc: states; 4分BEGINPROCESS(clk) BEGIN IF reset='1' then outc <=st0 ; 6分 elsif clk'event and clk='1' then CASE outc IS WHEN st0 => outc <= st1; 7分 WHEN st1 => outc <= st2; 8分 WHEN st2 => outc <= st3; 9分 WHEN st3 => outc <= st0; 10分 WHEN OTHERS => outc <=st0; END CASE; end if;END PROCESS;END arc; 4、设计异或门逻辑:(本题20分)如下异或门,填写右边的真值表。(此项5分)ABY000011101110其表达式可以表示为:(此项5分) 这一关系图示如下:试编写完整的VHDL代码实现以上逻辑。可以采用任何描述法。(此项10分)library ieee;use ieee.std_logic_1164.all; 1分entity yihuo1 isport(a,b:in std_logic;y:out std_logic);end yihuo1; 4分architecture yihuo1_behavior of yihuo1 isbegin 7分process(a,b) y<=a xor b;begin (第2种写法)if a=b theny<='0'elsey<='1'end if;end process; end yihuo1_behavior; 10分四、 编程(共50分,除特殊声明,实体可只写出PORT语句,结构体要写完整)1、用IF语句编写一个二选一电路,要求输入a、b, sel为选择端,输出q。(本题10分)Entity sel2 isPort (a,b : in std_logic;sel : in std_logic;q : out std_logic);End sel2;(3)Architecture a of sel2 isbeginif sel = 0 thenq <= a;(6)elseq <= b;(9)end if;end a;(10)2、编写一个4位加法计数器VHDL程序的进程(不必写整个结构框架),要求复位信号reset低电平时计数器清零,变高后,在上升沿开始工作;输入时钟信号为clk,输出为q。(本题10分)Process(reset,clk)(2)beginif reset = 0 thenq <= “0000”;(4)elsif clkevent and clk = 1 then(6)q <= q + 1;(9)end if;end process;(10)3、填写完成一个8-3线编码器的真值表(5分),并写出其VHDL程序(10分)。8 -3线编码器真值表enby0y1y21000000000001000000100011000001000101000010000111000100001001001000001011010000001101100000001110xxxxxxxx高阻态entity eight_tri is port(b:in std_logic_vector(7 downto 0);en:in std_logic;y:outstd_logic_vector(2 downto 0);end eight_tri;(3)architecture a of eight_tri is signal sel: std_logic_vector(8 downto 0);(4)beginsel<=en & b;y<= “000” when (sel=”100000001”)else“001” when (sel=”100000010”)else“010” when (sel=”100000100”)else“011” when (sel=”100001000”)else“100” when (sel=”100010000”)else“101” when (sel=”100100000”)else“110” when (sel=”101000000”)else“111” when (sel=”110000000”)else(9)“zzz”;(10)end a;4、根据已给出的全加器的VHDL程序,试写出一个4位逐位进位全加器的VHDL程序。(本题15分)library IEEE;use IEEE.std_logic_1164.all;use IEEE.std_logic_arith.all;use IEEE.std_logic_unsigned.all;entity adder isport (a,b,c:in std_logic;carr: inout std_logic;sum: out std_logic);end adder;architecture adder_arch of adder isbeginsum <= a xor b xor c;carr <= (a and b) or (b and c) or (a and c);end adder_arch;entity full_add isport (a,b: instd_logic_vector (3 downto 0);carr: inout std_logic_vector (4 downto 0);sum: outstd_logic_vector (3 downto 0);end full_add;(5)architecture full_add_arch of full_add iscomponent adderport (a,b,c:instd_logic;carr: inoutstd_logic;sum: out std_logic);end component;(10)begincarr(0)<='0'u0:adder port map(a(0),b(0),carr(0),carr(1),sum(0);u1:adder port map(a(1),b(1),carr(1),carr(2),sum(1);u2:adder port map(a(2),b(2),carr(2),carr(3),sum(2);u3:adder port map(a(3),b(3),carr(3),carr(4),sum(3);end full_add_arch;(15)四、 编程(共50分,除特殊声明,实体可只写出PORT语句,结构体要写完整)1、用IF语句编写一个四选一电路,要求输入d0d3, s为选择端,输出y。(本题10分)entity MUX4 is port(s:in std_logic_vector(1 downto 0);d:in std_logic_vector(3 downto 0);y:out std_logic);end MUX4; (3)architecture behave of MUX4 isbeginprocess(s)beginif (s="00") theny<=d(0); (4)elsif (s="01") theny<=d(1); (5)elsif (s="10") theny<=d(2); (6)elsif (s="11") theny<=d(3); (7)elsenull; (9)end if;end process;end behave; (10)2、编写一个数值比较器VHDL程序的进程(不必写整个结构框架),要求使能信号g低电平时比较器开始工作,输入信号p = q,输出equ为0,否则为1。(本题10分)process(p,q)(2)beginif g='0' then(4)if p = q thenequ_tmp <= '0'(6)else equ_tmp <= '1'(8)end if;else equ_tmp <= '1'(10)end if;end process;3、填写完成一个3-8线译码器的真值表(5分),并写出其VHDL程序(10分)。3-8译码器的真值表ena2a1a0y1000000000011001000000101010000001001011000010001100000100001101001000001110010000001111100000000xxx00000000entity tri_eight is port(a:in std_logic_vector (2 downto 0);en:in std_logic;y:outstd_logic_vector (7 downto 0);end tri_eight;(2)architecture a of tri_eight is signal sel:std_logic_vector (3 downto 0);(4)beginsel(0) <= a(0);sel(1) <= a(1);sel(2) <= a(2);sel(3) <= en;(5)with sel selecty <= "00000001" when "1000","00000010" when "1001","00000100" when"1010","00001000" when"1011","00010000" when"1100","00100000" when"1101","01000000" when"1110","10000000" when"1111","00000000" whenothers;(9)end a;(10)4、根据已给出的二-十(BCD)进制优先权编码器功能表,试写出其VHDL程序。(本题15分)二-十(BCD)进制优先权编码器功能表输入输出I1I2I3I4I5I6I7I8I9Y3Y2Y1Y01111111111111XXXXXXXX00110XXXXXXX010111XXXXXX0111000XXXXX01111001XXXX011111010XXX0111111011XX01111111100X0111111111010111111111110entity prior isport(d : in std_logic_vector(9 downto 1);q : out std_logic_vector(3 downto 0);end prior;(2)architecture behavior of prior is beginprocess(d)(4)2; "0 < = " = '= "" < ' ;0" ' ) "0"= 0 ) " < "" ' " = 0 " < 0=) " = ( ( )0 _ _ :) ( 输输能器权制)(分 本程 出写能码优) -二已0( ; 000"" "00"0" 000" 00 "0" 000"" " "00" 0 000"00 00"0" "00= (=) ) ) <) ;(=)( 0 _ ; _ )0 ( _ ) 00 00 00 0000000 00 0000000 值值器)0序 并, 真译 一写 0 = ' '0< ( ' ( 分0本。则否为 出= 入作始比电信求,构整不(序 器值个0( ( ;(< )"( (; < ; < )"= ( 0< 0= ( ) _ ) :) 分0本出,择, 入要路选写语 整写体, 出只,声,0程 ( _ ) (, ) :) , ) , )(, )( () ( ) ) 0 0)( :'') 00 ) _ :, _ _ )00 )0 : ) _ _ _ ) ( ) ) < =< ) _ _ : _ . 分 (序 位逐 写序程的全出据 0 ; 000” )00” 0000=( ” )00 = ” 0 0” ( ”0 000” 0 ”000 0 00” 0 & 0 ( _ )0 _ )0 : 阻 000 00000000 000 000 00000 值真码 )0 并分(真码-个完0( ( = ”0 , 分 题为, 为钟输工上后高清时低 信求框构必程序 数位写0(; ( ( ) _ : _ 分 (出,为 入求路一个语整整构, 出只,明特0(0 ''= '' 法法第 < , ) :, ; . 分0(述任以可以码代 完下图 )此为以式分 (表边填门分分本:或; ; > 0 < > = > 0 =