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LIBRARY ieee;
6 A" b8 q" p: J+ E5 L8 {USE ieee.std_logic_1164.all;: {7 }) {+ w6 i5 v
USE ieee.std_logic_unsigned.all;3 {# ~- J- M$ w$ v/ s% [
ENTITY counter_backwards60_seg2 IS
' y4 U, j/ f% o2 a" G6 ^! D PORT(Clrn,Load,Ena,Clk : IN STD_LOGIC;
; R* x# n5 e( H) G% f) Q0 \( R Ring : OUT STD_LOGIC;
* g; n, [% T8 C8 F Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ; 5 Z3 S( P$ S0 T' y: q6 H
END counter_backwards60_seg2;
$ }3 E2 K! H- E) J9 N) j+ W4 vARCHITECTURE arc OF counter_backwards60_seg2 IS
( P5 v# v5 j. S/ s$ }6 f BEGIN& |$ p- ^9 @; s8 g
PROCESS (Clk)9 x* i% N( w9 h4 q- P4 E
VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);
3 N {+ p9 s" X5 ^2 f VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0);' o e! o( f( x( `7 Q
BEGIN
( R& P1 ]4 N4 L8 e& W L k* W) N IF Clrn='0' THEN imper1 := "0110"; imper0 := "0000";; j: x' U4 k4 h- h. [
ELSE IF (Clk'event AND Clk='1') THEN
( ?' i0 B+ B# X( } IF Load='0' THEN imper1:="0110"; imper0:="0000";
! W6 K: F0 T9 o& V2 ` ELSIF Ena='1' THEN
$ `% _4 z+ |, M" w; w IF (imper0="1001" AND imper1="0101")THEN
/ W& w' d9 s3 W5 a+ c imper0 :="1000"; ( r4 E( P# w: b, J
ELSIF imper0 >"0000" THEN imper0 := imper0-1;
4 n" k0 ?* d: Y5 _* y$ I U9 ]; t! W+ K C ELSE imper0:="1001";
9 E5 x, i1 d( _, V4 h+ i& T IF imper1 >"0000" THEN imper1 := imper1-1;6 f' H6 t+ k. j0 V8 ]
ELSE imper1:="0101";
0 K! a ^/ P! D" a4 `( X$ l$ P END IF;9 l" g u& b% l* o# m7 z
END IF; ' _$ |+ G6 g; U( ]* t/ j# _# C
END IF;$ U5 u- A2 X* k
END IF;* U+ L- C: u0 |5 E0 [2 o. W
END IF; 4 Y" m4 ]! ]2 X0 `# D4 V
Q0 <= imper0; Q1 <= imper1; ; s6 n( L; x- u7 Z/ z# D5 N0 b3 L) p
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));
- \! J& Z% o" Q1 { END PROCESS ;
2 B0 w q# n4 iEND arc;# h# f# N3 O; l
* x+ M H# p. ?0 X& U上面是我的倒數60秒程式
! u! V# t) \6 ^/ w+ \# n' p( J- {7 D小弟不才' J5 E3 s+ {( J0 g3 q, t ~& J2 j
不知道怎寫停止4 r, g$ X6 A: W' ?
只要數1次60就好 |
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