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LIBRARY ieee;
8 I p6 t! W" s2 n5 f( lUSE ieee.std_logic_1164.all;, Y$ u2 k& {4 \# ^
USE ieee.std_logic_unsigned.all;
0 S" o* c- f( n9 f. [$ i6 bENTITY counter_backwards60_seg2 IS" s' W- F. z( J5 c
PORT(Clk : IN STD_LOGIC;
6 M4 p3 {9 I1 a% a Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ; ! `; @" i+ R* ~: G, q* N- s
END counter_backwards60_seg2;
+ E7 v( f: f) I5 @5 T) \ARCHITECTURE arc OF counter_backwards60_seg2 IS
5 M9 w: g' O7 m) J, W( }7 i$ r; r BEGIN
" g3 k P3 c& E8 w V9 K PROCESS (Clk)
8 v4 `. t' E7 N; f VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);
3 w2 i# f: L/ d% |* B% m" S VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0);
/ p( [" Q2 M; n4 @3 R/ l BEGIN
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IF (Clk'event AND Clk='1') THEN
# k+ v1 |! q2 b % i. @. F. \# P) S. h4 k) ~
IF imper0 >"0000" THEN imper0 := imper0-1;( t& V3 B9 ]$ W/ y, Q; {4 E
ELSE imper0:="1001";) p4 X8 |8 L2 K
IF imper1 >"0000" THEN imper1 := imper1-1;, F$ v: Y- h6 ^9 l0 ~
ELSE imper1:="0101";
# ?+ J8 i# M, ~5 O( h% x+ C; s END IF;7 a# g3 V8 R: M! z, C
END IF; 7 a8 d, `4 f2 ~ y
END IF; : ~+ M; O& O1 \+ f
Q0 <= imper0; Q1 <= imper1;
7 T* K! L1 a ]& j# u% p# F END PROCESS ;8 n7 Y" O+ J& R9 F
END arc;( N9 W1 t4 k: C7 U& { S
以上我精簡了一些 也能跑模擬圖
- ? M, Z* t/ _! ?. S) `- z X1 Y但現在重點是我該怎寫60→59→58...
: M+ Z- F, R- P4 h初始值60要怎寫...
. u( o( {- c1 a. T7 q$ C% ]. y是要多2個input 然後給他一開始的值?! D: p: o# k# a: ]/ B. T
但要怎寫啊@@...
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