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LIBRARY ieee;
" ^6 s- ]# I* W% l5 EUSE ieee.std_logic_1164.all;
8 M! B$ v( P9 M K, \9 u9 bUSE ieee.std_logic_unsigned.all;& I6 h- K' B* F8 t3 j
ENTITY counter_backwards60_seg2 IS6 f7 K* a$ M$ v# L
PORT(Clrn,Load,Ena,Clk : IN STD_LOGIC;) |/ \$ B3 Q8 K! I" c
Ring : OUT STD_LOGIC; 9 s8 m: r! H: B$ i$ B
Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ;
/ i% p: ~" l6 }3 U0 H( vEND counter_backwards60_seg2;) J7 V3 m+ z. Y. }4 G, N
ARCHITECTURE arc OF counter_backwards60_seg2 IS
6 r$ n0 s q8 t0 P1 Z ^. N7 G BEGIN+ a+ t9 a" p! N6 L" l
PROCESS (Clk)
. G+ g% W% B5 r VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);9 C) _0 }5 [* V' N- H" c/ `
VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0);
, S6 U$ S9 T; Y& C) W BEGIN
3 ]; l+ Q- N1 N' X! |! g+ g IF Clrn='0' THEN imper1 := "0110"; imper0 := "0000";0 s. j) G# f3 @
ELSE IF (Clk'event AND Clk='1') THEN 1 Z* a! S X" \
IF Load='0' THEN imper1:="0110"; imper0:="0000";
9 N4 Q4 o: P9 ~* K* H ELSIF Ena='1' THEN
3 c3 T7 o3 [+ }. D" g; e9 c0 [4 p IF (imper0="1001" AND imper1="0101")THEN
% y+ z! h5 q0 j6 u imper0 :="1000"; $ C8 M4 j4 F( T
ELSIF imper0 >"0000" THEN imper0 := imper0-1;% O& G$ E& i( _2 D
ELSE imper0:="1001";6 E' R4 {: @8 i; y, h
IF imper1 >"0000" THEN imper1 := imper1-1;- \7 _/ M1 s9 V. r+ K% d: G- v
ELSE imper1:="0101"; $ ?* Y+ y# Y) o$ b+ p% F: {7 m: j
END IF;0 ~0 u: c7 }* R# u
END IF;
* ^. H# p0 `' D; n9 s END IF;
7 }. x% \! }( \+ W9 L0 \& x& j& Z END IF;
/ R ~/ R+ e! G) G END IF; 4 k! O' o, b& Y* B& @
Q0 <= imper0; Q1 <= imper1; % ?3 e- k& d8 G* g+ E
Ring <= not(imper0(0) or imper0(1) or imper0(2) or imper0(3) or imper1(0) or imper1(1) or imper1(2) or imper1(3)); * ]" h, C8 I% T3 ?. Q# m, K5 {9 ?
END PROCESS ;$ x8 y9 h$ K5 j) O, l+ R
END arc;( {6 {9 C: |/ s
o x0 g5 r; l( @% {3 g上面是我的倒數60秒程式* M8 K5 ^% }0 @. b: ]
小弟不才3 N+ \7 v2 Z/ \( f
不知道怎寫停止
, P( _, @7 ^1 F" g只要數1次60就好 |
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