---------------------------------------------------------------------------
----FileName:fq_divider.vhd
----该模块为分频器，将1KHZ的时钟频率分频成每分钟一次的时钟频率
----事实上，该源码可以实现任意整数的分频，主要让N的值设置好相应的数字
---------------------------------------------------------------------------
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY fq_divider IS
generic(n:integer:=60000);
PORT(
CLK,reset: IN STD_LOGIC;
CLK_OUT:buffer STD_LOGIC
);
END;
ARCHITECTURE A OF fq_divider IS
SIGNAL CNT1,CNT2:integer:=0;
SIGNAL OUTTEMP:STD_LOGIC;
SIGNAL LOUT:STD_LOGIC;
SIGNAL OUT3:STD_LOGIC:='0';
BEGIN
P1:PROCESS(CLK)
BEGIN
IF CLK'EVENT AND CLK='1' THEN
?? IF CNT1=n-1 THEN
????? CNT1<=0;
?? ELSE
????? CNT1<=CNT1+1;
?? END IF;
END IF;
END PROCESS P1;
P2:PROCESS(CLK)
BEGIN
IF CLK'EVENT AND CLK='0' THEN
?? IF CNT2=n-1 THEN
????? CNT2<=0;
?? ELSE
????? CNT2<=CNT2+1;
?? END IF;
END IF;
END PROCESS P2;
P3:PROCESS(CNT1,CNT2 )
BEGIN
if ((n mod 2)=1) then
?? IF CNT1=1 THEN
????? IF CNT2=0 THEN
???????? OUTTEMP<='1';
????? ELSE
???????? OUTTEMP<='0';
????? END IF;

??? ELSIF CNT1=(n+1)/2 THEN
????????? IF CNT2=(n+1)/2 THEN
???????????? OUTTEMP<='1';
????????? ELSE OUTTEMP<='0';
????????? END IF;

??? ELSE
????????? OUTTEMP<='0';
??? END IF;
?? else
??? if cnt1=1 then
?????? outtemp<='1';
??? elsif (cnt1=(n/2+1)) then
?????? outtemp<='1';
??? else
?????? outtemp<='0';
? end if;
end if;
END PROCESS P3;
P4:PROCESS(OUTTEMP,clk,reset)
BEGIN
if reset='0' then
?? clk_out<=clk;
elsif ((n/=2) and (n/=1)) then
?? IF OUTTEMP'EVENT AND OUTTEMP='1' THEN
????? CLK_OUT<=NOT CLK_OUT;
?? END IF;
elsif (n=2) then
?? if(clk'event and clk='1')then
????? clk_out<=not clk_out;
?? end if;
else
?? clk_out<=clk;
end if;
END PROCESS P4;
END A;