VHDL自动售邮票机的代码.doc

自动售邮票机代码：library ieee;use ieee.std_logic_1164.all;use ieee.std_logic_arith.all;use ieee.std_logic_unsigned.all;entity xrg4 is port(clk,clk1:in bit; coin1,coin5,coin10:in std_logic; -投入1、5、10角硬币 reset,reset1:in std_logic; -清零信号,1有效 six,eight:in std_logic; -6，8角的邮票 light:out std_logic; -购买成功指示灯 retlight:out std_logic_vector(3 downto 0) ); -找回的硬币end entity xrg4;architecture xxrr of xrg4 is type state is (s0,s1,s2);-状态机 signal n_state:state;-次态 signal c_state:state;-现态 signal touru:std_logic_vector(3 downto 0); -投入硬币面值 signal tincoint:std_logic_vector(4 downto 0);-计算出硬币总值（进程中） signal stamp:std_logic_vector(3 downto 0); -邮票面值 signal ret:std_logic_vector(3 downto 0); -找零值 signal zong:std_logic_vector(4 downto 0); -状态机硬币总值 begin p1:process(clk1) -次态给现态 begin if reset1=1then c_state=s2; elsif clk1event and clk1=1then c_state=n_state; end if; end process p1; p2:process(clk) -投入钱并计算总值 begin if reset1=1then tincoint=00000; elsif clkevent and clk=1 then if coin1=1then touru=0001; elsif coin5=1then touru=0101; elsif coin10=1then touru=1010; elsif coin1=0 and coin5=0 and coin10=0 then touru=0000; end if; tincoint=touru+tincoint; end if; end process p2; p3:process(c_state) -进行购买，找零，退钱 begin zong if six=1 then stamp=0110;n_state=s1; -选通6角或8角邮票 elsif eight=1 then stamp=1000; n_state=s1; else zong=00000;ret=0000;light=0;n_state if zongstamp then if reset=1 then ret=zong(3 downto 0); n_state=stamp then light=1;ret if six=1or eight=1thenret=zong(3 downto 0);light=0;zong=00000; n_state retlight retlight retlight retlight retlight retlight