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LIBRARY ieee; " Y! I! z J) a5 Z
USE ieee.std_logic_1164.all;& j; v: J8 c+ X) `) P+ k. m2 I
USE ieee.std_logic_unsigned.all;
$ u* `9 U2 `# M! S: Z: mENTITY counter_backwards60_seg2 IS
2 r) ]& L( f. D" W7 X+ w, Z PORT(Clrn,Load,Ena,Clk : IN STD_LOGIC;
# L# G& T0 s0 q" `( G. a2 M7 O3 g Ring : OUT STD_LOGIC;
# G" l- N6 [; M Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ; 3 I+ I# i: X0 G% m s- v
END counter_backwards60_seg2;
: X7 ~; i# V: q$ m: E3 C6 sARCHITECTURE arc OF counter_backwards60_seg2 IS4 j+ n$ e( @7 c8 F5 H' p
BEGIN
! { M/ U1 L& I2 `5 ` PROCESS (Clk)% V# _5 ~4 |; }* y4 b/ J3 O+ S
VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);6 U% R5 i \' K6 k
VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0);/ ]6 u' J6 \2 J' z0 F6 i- O, l
BEGIN/ n. V- Z' M# @* @
IF Clrn='0' THEN imper1 := "0110"; imper0 := "0000";
1 I" @6 m! B9 A0 _# d) E ELSE IF (Clk'event AND Clk='1') THEN 7 X/ b+ s$ E' p- p& m3 W; Z: {
IF Load='0' THEN imper1:="0110"; imper0:="0000";
$ J8 ~% C8 `/ w3 l7 e ELSIF Ena='1' THEN; k; k R7 \' ?/ B1 |7 [
IF (imper0="1001" AND imper1="0101")THEN
- H X2 u3 c' ~- { imper0 :="1000";
: ]' a/ Q% C, f# n% Q7 s ELSIF imper0 >"0000" THEN imper0 := imper0-1;$ v: q- b9 c( }; m9 b0 ?9 L5 w
ELSE imper0:="1001";
, o. T( F8 r0 C8 e) Y8 F! V9 j IF imper1 >"0000" THEN imper1 := imper1-1;' ?2 o! V1 R8 K% ~
ELSE imper1:="0101"; $ R4 g4 [/ A) p( ^3 ^- }% W% J
END IF;8 H5 [. z; J \. g
END IF;
5 T8 h- C0 v$ {/ P" ~+ Q7 |, n END IF;
4 n- N& F% h; n6 ^$ x( t" | END IF;
5 B9 ^, G( i0 C8 j: a# ` END IF; # q V- g/ ~) T: h L
Q0 <= imper0; Q1 <= imper1; & J0 ?3 Y2 N3 Y/ f) z5 L+ b
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));
3 Y( @, V( h7 l: k5 {2 W# u' V: {2 W END PROCESS ;
. ]! y5 R$ O2 B" P3 P! d) z8 ~5 e% U5 pEND arc;9 F+ y9 m B- |* t0 C
( c( [- \- g0 ^/ A8 b. {; Y. w; I
上面是我的倒數60秒程式
8 ]4 j! J/ j- f小弟不才
9 S! z( }& L5 h不知道怎寫停止' ]9 \& L8 r/ T" ]$ d
只要數1次60就好 |
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