用VHDL語言設(shè)計(jì)555壓控振蕩器測(cè)頻率

1、實(shí)驗(yàn)五 利用壓控振蕩器測(cè)量電壓一、實(shí)驗(yàn)?zāi)康模?）以555定時(shí)器為基礎(chǔ)設(shè)計(jì)壓控振蕩器（2）設(shè)計(jì)一個(gè)具有如下功能的簡(jiǎn)易頻率計(jì)。 1. 可以測(cè)量壓控振蕩器產(chǎn)生的頻率，用4位數(shù)碼管顯示 2.測(cè)量結(jié)果直接用十進(jìn)制數(shù)值顯示 3. 被測(cè)信號(hào)是壓控振蕩器產(chǎn)生的方波脈沖信號(hào)，根據(jù)設(shè)計(jì)的壓控振蕩器確定電壓值 4. 具有超量程警告（可以用 LED 燈顯示）二、實(shí)驗(yàn)設(shè)備與器材（1）計(jì)算機(jī)：Quartus 16.0軟件；（2）硬件：Cyclone DE0-CV FPGA開發(fā)平臺(tái)、555定時(shí)器、電阻、電容、可變電阻三、利用Multisim搭建仿真電路四、實(shí)驗(yàn)程序library ieee;use ieee.std_logi

2、c_1164.all;use ieee.std_logic_unsigned.all;- 計(jì)數(shù)器entity cnt10 is port (rst,fx,ena:in std_logic; cout: out std_logic; outy :out std_logic_vector(3 downto 0);end cnt10;architecture behv of cnt10 isbegin process (rst,ena,fx) - 定義變量 - <=是對(duì)信號(hào)賦值；而:=是對(duì)變量進(jìn)行賦值 variable cqi :std_logic_vector(3 downto 0); be

3、gin - others =>'0'是對(duì)數(shù)組cqi所有元素賦值0 if rst='1' then cqi :=(others =>'0'); elsif fx'event and fx='1' then if ena ='1' then if cqi < 9 then cqi:=cqi+1;cout<='0' elsif cqi=9 then cqi :=(others =>'0'); cout<='1' end if; e

4、lsif ena='0' then cqi:=(others =>'0'); end if; end if; outy <=cqi; end process;end behv;- 4位10進(jìn)計(jì)數(shù)器library ieee;use ieee.std_logic_1164.all;entity cnt10_4 isport(fx,rst,ena,clk:in std_logic;d:out std_logic_vector(15 downto 0); led_a:out std_logic);end entity;architecture one of

5、cnt10_4 iscomponent cnt10 port (rst,fx,ena:in std_logic; cout: out std_logic; outy :out std_logic_vector(3 downto 0);end component;component led_heheport(ena,clk:in std_logic;q:out std_logic);end component;signal e:std_logic_vector(3 downto 0);begin- 整體使用相同的rst和ena，fx作為進(jìn)位使用。u1:cnt10 port map(fx=>

6、fx,rst=>rst,ena=>ena,cout=>e(0),outy=>d(3 downto 0);u2:cnt10 port map(fx=>e(0),rst=>rst,ena=>ena,cout=>e(1),outy=>d(7 downto 4);u3:cnt10 port map(fx=>e(1),rst=>rst,ena=>ena,cout=>e(2),outy=>d(11 downto 8);u4:cnt10 port map(fx=>e(2),rst=>rst,ena=>ena

7、,cout=>e(3),outy=>d(15 downto 12);u5:led_hehe port map(ena=>e(3),clk=>clk,q=>led_a);end architecture one;- 16位鎖存器 latch=閂library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_unsigned.all;entity latch4 isport(d:in std_logic_vector(15 downto 0);ena,clk:in std_logic;q:out std_logi

8、c_vector(15 downto 0);end latch4;architecture one of latch4 isbegin process(clk,ena,d) variable cqi:std_logic_vector(15 downto 0); begin if ena='0' then cqi:=cqi;- ena=0 鎖存上次的數(shù)據(jù) elsif clk'event and clk='1' then cqi:=d;-clk=1&&ena=1 計(jì)入新數(shù)據(jù) end if; q<=cqi; end process; en

9、d one;- 報(bào)警led hehelibrary ieee;use ieee.std_logic_1164.all;use ieee.std_logic_unsigned.all;entity led_hehe isport(ena,clk:in std_logic;q:out std_logic);end led_hehe;architecture one of led_hehe isbegin process(clk,ena) variable cqi:std_logic; begin if ena='0' then cqi:=cqi;- ena=0 鎖存上次的數(shù)據(jù) el

10、sif clk'event and clk='1' then cqi:= not cqi;-clk=1&&ena=1 計(jì)入新數(shù)據(jù) end if; q<=cqi; end process;end one;- LED控制模塊(數(shù)碼管controller)library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_unsigned.all;entity led_controller isport(d:in std_logic_vector(3 downto 0);a:out std_logic_

11、vector(6 downto 0);end led_controller;architecture one of led_controller isbegin process(d) begin case d is when "0000"=> a<="1000000"when "0001"=> a<="1111001" when "0010"=> a<="0100100"when "0011"=> a<=&q

12、uot;0110000" when "0100"=> a<="0011001"when "0101"=> a<="0010010" when "0110"=> a<="0000010"when "0111"=> a<="1111000" when "1000"=> a<="0000000"when "1001"

13、;=> a<="0010000" when "1010"=> a<="0001000"when "1011"=> a<="0000011" when "1100"=> a<="1000110"when "1101"=> a<="0100001" when "1110"=> a<="0000110"when

14、"1111"=> a<="0001110" when others=> null; end case; end process;end;- 控制模塊(每隔一次clk，就翻轉(zhuǎn)ena和rst)library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_unsigned.all;entity control is port (clk:in std_logic; rst,ena: out std_logic);end control;architecture behv of contr

15、ol isbegin process (clk) variable cqi :std_logic_vector(2 downto 0); begin if clk'event and clk='1' then if cqi <1 then cqi:=cqi+1;ena<='1'rst<='0' elsif cqi=1 then cqi :=(others =>'0'); ena<='0'rst<='1' end if; end if; end proces

16、s;end behv;- 時(shí)鐘（1hz）發(fā)生器library ieee;use ieee.std_logic_1164.all;entity freq_div is port (clk:in std_logic; clk_out:out std_logic); end freq_div;architecture fwm of freq_div isconstant m: integer:= 25000;signal tmp:std_logic;begin process(clk,tmp) variable cout:integer:=0; begin if clk'event and

17、clk='1' then cout:=cout+1; if cout<=m then tmp<='0' elsif cout<m*2 then tmp<='1' else cout:=0; end if; end if; end process;clk_out<=tmp;end fwm;- 總體例化語句：library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_unsigned.all;- clk是50hz的板載時(shí)鐘信號(hào)，即參考信號(hào)，而fx才是測(cè)量的輸入信

18、號(hào)entity voc isport(clk:in std_logic;fx:in std_logic;ledout:out std_logic_vector(28 downto 0);- 數(shù)碼管7*4end entity;architecture one of voc iscomponent freq_div port (clk:in std_logic; clk_out:out std_logic);end component;component control port (clk:in std_logic; rst,ena: out std_logic);end component;co

19、mponent cnt10_4port(clk,fx,rst,ena:in std_logic;d:out std_logic_vector(15 downto 0); led_a:out std_logic);end component;component latch4port(d:in std_logic_vector(15 downto 0);ena,clk:in std_logic;q:out std_logic_vector(15 downto 0);end component;component led_controllerport(d:in std_logic_vector(3

20、downto 0);a:out std_logic_vector(6 downto 0);end component;signal x,z:std_logic;signal g,h:std_logic_vector(15 downto 0);signal leds:std_logic_vector(28 downto 0);signal clk_base:std_logic;beginu1: freq_div port map(clk=>clk,clk_out=>clk_base);u2: control port map(clk=>clk_base,ena=>x,rst=>z);u3: cnt10_4 port map(fx=>fx,rst=>z,ena=>x,d=>g,led_a=>leds(28),clk=>clk_base);u4: latch4 port map(clk=>clk_base,ena=>x,d=>g,q