VHDL复习题

内容发布更新时间 : 2024/11/17 0:17:25星期一 下面是文章的全部内容请认真阅读。

. Process(clk,rst) Begin

If rst=’0’ then

Count<=(others=>’0’) ; If en=’1’ then

When ‘1’ => count<=count+1; When others =>count<=count-1;

Elsif rising_edge(clk) then

Case up is

End case;

End if;

End if;

End process;

Sum<=count;

Cout <=’1’ when en=’1’ and ((up=’1’ and count=7) or (up=’0’ and count=0)) else

‘0’; End a; 2.仔细阅读下列程序,回答问题

LIBRARY IEEE; USE IEEE.STD_LOGIC_1164.ALL; ENTITY LED7SEG IS PORT ( A : IN STD_LOGIC_VECTOR(3 DOWNTO 0); CLK : IN STD_LOGIC; LED7S : OUT STD_LOGIC_VECTOR(6 DOWNTO 0)); END LED7SEG; ARCHITECTURE one OF LED7SEG IS SIGNAL TMP : STD_LOGIC; BEGIN SYNC : PROCESS(CLK, A) BEGIN IF CLK'EVENT AND CLK = '1' THEN TMP <= A; END IF; END PROCESS; OUTLED : PROCESS(TMP) BEGIN CASE TMP IS WHEN \

-- 1

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11 / 12

. WHEN \ WHEN \ WHEN \ WHEN \ WHEN \ WHEN \ WHEN \ WHEN \ WHEN \ END CASE; END PROCESS; END one; 1)在程序中存在两处错误,试指出,并说明理由: 2)修改相应行的程序:

错误1 行号: 程序改为:

错误2 行号: 程序改为: 12 / 12

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