下面程序是1位十进制计数器的VHDL描述.doc

下面程序是1位十进制计数器的VHDL描述，试补充完整。 2. 下面是一个多路选择器的VHDL描述，充完整。

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY CNT10 IS
PORT ( CLK : IN STD_LOGIC ;
Q : OUT STD_LOGIC_VECTOR(3 DOWNTO 0)) ;
END CNT10;

ARCHITECTURE bhv OF CNT10 IS
SIGNAL Q1 : STD_LOGIC_VECTOR(3 DOWNTO 0);
BEGIN
PROCESS (CLK)
BEGIN
IF CLK'EVENT AND CLK = '1' THEN -- 边沿检测
IF Q1 > 10 THEN
Q1 <= (OTHERS => '0'); -- 置零
ELSE
Q1 <= Q1 + 1 ; -- 加1
END IF;
END IF;
END PROCESS ;
Q <= Q1;
END bhv;
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY bmux IS
PORT ( sel : IN STD_LOGIC;
A, B : IN STD_LOGIC_VECTOR(7 DOWNTO 0);
Y : OUT STD_LOGIC_VECTOR(7 DOWNTO 0)) ;
END bmux;
ARCHITECTURE bhv OF bmux IS
BEGIN
y <= A when sel = '1' ELSE
B;
END bhv;
三、VHDL程序改错
仔细阅读下列程序，回答问题
LIBRARY IEEE; -- 1
USE IEEE.STD_LOGIC_1164.ALL; -- 2
ENTITY LED7SEG IS -- 3
PORT ( A : IN STD_LOGIC_VECTOR(3 DOWNTO 0); -- 4
CLK : IN STD_LOGIC; -- 5
LED7S : OUT STD_LOGIC_VECTOR(6 DOWNTO 0)); -- 6
END LED7SEG; -- 7
ARCHITECTURE one OF LED7SEG IS -- 8
SIGNAL TMP : STD_LOGIC; -- 9
BEGIN -- 10
SYNC : PROCESS(CLK, A) -- 11
BEGIN -- 12
IF CLK'EVENT AND CLK = '1' THEN -- 13
TMP <= A; -- 14
END IF; -- 15
END PROCESS; -- 16
OUTLED : PROCESS(TMP) -- 17
BEGIN -- 18
CASE TMP IS -- 19
WHEN "0000" => LED7S <= "0111111"; -- 20
WHEN "0001" => LED7S <= "0000110"; -- 21
WHEN "0010" => LED7S <= "1011011"; -- 22
WHEN "0011" => LED7S <= "1001111"; -- 23
WHEN "0100" => LED7S <= "1100110"; -- 24
WHEN "0101" => LED7S <= "1101101"; -- 25
WHEN "0110" => LED7S <= "1111101"; -- 26
WHEN "0111" => LED7S <= "0000111"; -- 27
WHEN "1000" => LED7S <= "1111111"; -- 28
WHEN "1001" => LED7S <= "1101111"; -- 29
END CASE; -- 30
END PROCESS; -- 31
END one; -- 32
1. 在程序中存在两处错误，试指出，并说明理由：
第14行 TMP附值错误 第29与30行之间，缺少WHEN OTHERS语句
2 修改相应行的程序：
错误1 行号： 9 程序改为： TMP : STD_LOGIC_VECTOR(3 DOWNTO 0);
错误2 行号： 29 程序改为：该语句后添加 WHEN OTHERS => LED7S <= "0000000";
四、阅读下列VHDL程序，画出原理图（RTL级）
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY HAD IS
PORT ( a : IN STD_LOGIC;
b : IN STD_LOGIC;
c : OUT STD_LOGIC;
d : OUT STD_LOGIC);
END ENTITY HAD;
ARCHITECTURE fh1 OF HAD IS
BEGIN
c <= NOT(a NAND b);
d <= (a OR b)AND(a NAND b);
END ARCHITECTURE fh1;

五、请按题中要求写出相应VHDL程序
1. 带计数使能的异步复位计数器
输入端口： clk 时钟信号
rst 异步复位信号
en 计数使能
load 同步装载
data （装载）数据输入，位宽为10
输出端口： q 计数输出，位宽为10
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY CNT1024 IS
PORT ( CLK, RST, EN, LOAD : IN STD_LOGIC;
DATA : IN STD_LOGIC_VECTOR (9 DOWNTO 0);
Q : OUT STD_LOGIC_VECTOR (9 DOWNTO 0) );
END CNT1024;
ARCHITECTURE ONE OF CNT1024 IS
BEGIN
PROCESS (CLK, RST, EN, LOAD, DATA)
VARIABLE Q1 : STD_LOGIC_VECTOR (9 DOWNTO 0);
BEGIN
IF RST = '1' THEN
Q1 := (OTHERS => '0');
ELSIF CLK = '1' AND CLK'EVENT THEN
IF LOAD = '1' THEN
Q1 := DATA;
ELSE
IF EN = '1' THEN
Q1 := Q1 + 1;
END IF;
END IF;
END IF;
Q <= Q1;
END PROCESS;
END ONE;
2 看下面原理图，写出相应VHDL描述

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY TRI_STATE IS
PORT ( E, A : IN STD_LOGIC;
Y : INOUT STD_LOGIC;
B : OUT STD_LOGIC);
END TRI_STATE;
ARCHITECTURE BEHAV OF TRISTATE IS
BEGIN
PROCESS (E, A, Y)
BEGIN
IF E = '0' THEN
B <= Y;
Y <= 'Z';
ELSE
B <= 'Z';
Y <= A;
END IF;
END PROCESS;
END BEHAV;
六、综合题
下图是一个A/D采集系统的部分，要求设计其中的FPGA采集控制模块，该模块由三个部分构成：控制器（Control）、地址计数器（addrcnt）、内嵌双口RAM（adram）。控制器（control）是一个状态机，完成AD574的控制，和adram的写入操作。Adram是一个LPM_RAM_DP单元，在wren为’1’时允许写入数据。试分别回答问题

下面列出了AD574的控制方式和控制时序图

CE
CS
RC
K12_8
A0
工 作 状 态
0
X
X
X
X
禁止
X
1
X
X
X
禁止
1
0
0
X
0
启动12位转换
1
0
0
X
1
启动8位转换
1
0
1
1
X
12位并行输出有效
1
0
1
0
0
高8位并行输出有效
1
0
1
0
1
低4位加上尾随4个0有效

AD574逻辑控制真值表（X表示任意）

AD574工作时序：

1. 要求AD574工作在12位转换模式，K12_8、A0在control中如何设置
K12_8为‘1’，A0为‘0’
2. 试画出control的状态机的状态图
类似书上图8-4
3. 对地址计数器模块进行VHDL描述
输入端口：clkinc 计数脉冲
cntclr 计数器清零
输出端口：rdaddr RAM读出地址，位宽10位
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity addr_cnt is
port ( clkinc, cntclr : in std_logic;
wraddr : out std_logic_vector (9 downto 0) );
end addr_cnt;
architecture one of addr_cnt is
signal tmp : std_logic_vector (9 downto 0);
begin
process (clkinc, cntclr)
begin
if clkinc'event and clkinc = '1' then
if cntclr = '1' then
tmp <= (others => '0');
else
tmp <= tmp + 1;
end if;
end if;
end process;
wraddr <= tmp;
end one;

4. 根据状态图，试对control进行VHDL描述
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity control is
port ( addata : in std_logic_vector (11 downto 0);
status, clk : in std_logic;
cs, ce, a0, rc, k12_8, clkinc : out std_logic;
rddata : out std_logic_vector (11 downto 0) );
end control;
architecture behav of control is
type con_st is (s0, s1, s2, s3, s4);
signal cst, nst : con_st;
signal lock : std_logic;
signal reg12 : std_logic_vector (11 downto 0);
begin
a0 <= '0';
k12_8 <= '1';
ce <= '1';
cs <= '0';
REGP : process (clk)
begin
if clk'event and clk = '1' then
cst <= nst;
end if;
end process;
COMP : process (cst, status, addata)
begin
case (cst) is
when s0 => rc <= '1'; lock <= '0'; nst <= s1;
when s1 => rc <= '0'; lock <= '0'; nst <= s2;
when s2 => if status = '1' then nst <= s3; end if;
rc <= '1'; lock <= '0';
when s3 => rc <= '1'; lock <= '1'; nst <= s4;
when s4 => rc <= '1'; lock <= '0'; nst <= s0;
when others => nst <= s0;
end case;
end process;
LOCKP process (lock)
begin
if lock = '1' and lock'event then
reg12 <= addata;
end if;
end process;
rddata <= reg12;
clkinc <= lock; --(或者为NOT LOCK，延后半个时钟)
end behav;

5. 已知adram的端口描述如下
ENTITY adram IS
PORT
(
data : IN STD_LOGIC_VECTOR (11 DOWNTO 0); -- 写入数据
wraddress: IN STD_LOGIC_VECTOR (9 DOWNTO 0); -- 写入地址
rdaddress: IN STD_LOGIC_VECTOR (9 DOWNTO 0); -- 读地址
wren : IN STD_LOGIC := '1'; -- 写使能
q : OUT STD_LOGIC_VECTOR (11 DOWNTO 0) -- 读出数据
);
END adram;
试用例化语句，对整个FPGA采集控制模块进行VHDL描述
library ieee;
use ieee.std_logic_1164.all;
entity daco is
port ( clk, cntclr, status : in std_logic;
addata : in std_logic_vector (11 downto 0);
rdaddr : in std_logic_vector (9 downto 0);
cs, ce, a0, rc, k12_8 : out std_logic;
rddata : out std_logic_vector (11 downto 0) );
end daco;
architecture one of daco is
component control is
port ( addata : in std_logic_vector (11 downto 0);
status, clk : in std_logic;
cs, ce, a0, rc, k12_8, clkinc : out std_logic;
rddata : out std_logic_vector (11 downto 0) );
end component;
component addr_cnt is
port ( clkinc, cntclr : in std_logic;
wraddr : out std_logic_vector (9 downto 0) );
end component;
component adram IS PORT
(data : IN STD_LOGIC_VECTOR (11 DOWNTO 0); -- 写入数据
wraddress: IN STD_LOGIC_VECTOR (9 DOWNTO 0); -- 写入地址
rdaddress: IN STD_LOGIC_VECTOR (9 DOWNTO 0); -- 读地址
wren : IN STD_LOGIC := '1'; -- 写使能
q : OUT STD_LOGIC_VECTOR (11 DOWNTO 0) -- 读出数据
);
END component;
signal rds : std_logic_vector (11 downto 0);
signal clkinc : std_logic;
signal wraddr : std_logic_vector (9 downto 0);
begin
u1 : control port map (addata => addata, status => status,
clk => clk, cs => cs, ce => ce, a0 => a0, rc => rc,
k12_8 > k12_8, clkinc => clkinc, rddata => rds);
u2 : addr_cnt port map (clkinc => clkinc, cntclr => cntclr, wraddr => wraddr);
u3 : adram port map (data => rds, wraddress => wraddr,
rdaddress => rdaddr, wren => '1', q => rddata);
end one;
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY three IS
PORT
(
clk,d : IN STD_LOGIC;
dout : OUT STD_LOGIC );
END;
ARCHITECTURE bhv OF three IS
SIGNAL tmp: STD_LOGIC;
BEGIN
P1: PROCESS(clk)
BEGIN
IF rising_edge(clk) THEN
Tmp <= d;
dout <= tmp;
END IF;
END PROCESS P1;
END bhv;

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