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LIBRARY ieee; 8 A6 _4 A8 C1 d7 x8 o5 ?
USE ieee.std_logic_1164.all;
% x8 J) A- L$ U& Y# ]+ bUSE ieee.std_logic_unsigned.all;# b, Y) w0 a( J- h9 {2 a; K
ENTITY counter_backwards60_seg2 IS
7 L* h3 k" L/ C f- I PORT(Clk : IN STD_LOGIC; 8 n( A; ^! ?( L4 F9 K1 K7 Q
Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ;
/ t- c1 a1 [ w rEND counter_backwards60_seg2;; I2 S* a" k l0 v5 O0 `# L
ARCHITECTURE arc OF counter_backwards60_seg2 IS3 p, u% @& w$ y& Y7 n
BEGIN/ x8 `, l. r7 d6 x9 F1 \
PROCESS (Clk)) c, G0 S; v4 B+ B: e
VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);
( A8 u* Y4 H% B" W! i0 q& O VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0); j" ~; s$ b& D( [9 `$ |
BEGIN
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IF (Clk'event AND Clk='1') THEN $ v" L/ r* w1 l f5 Y+ G" r( W
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IF imper0 >"0000" THEN imper0 := imper0-1;" b1 g) s: J8 K# A1 u. v7 o. D
ELSE imper0:="1001";( i# T2 b) _" G }6 q4 x
IF imper1 >"0000" THEN imper1 := imper1-1;
- x, ?* W. _3 Q: A L( H. C: D ELSE imper1:="0101"; 6 Z! s0 ]$ u7 x& Q: A& x
END IF;
6 E6 z% F& M, c7 F END IF; 4 Y1 l; A. b7 F/ D0 m" @
END IF;
! X: m* n3 A6 D3 }. a) [( Z Q0 <= imper0; Q1 <= imper1;
6 g. N; H! t" Q# A9 g, V4 Z3 e END PROCESS ;
4 m9 b3 E" v7 w" a4 y, A3 ^END arc; m! r: m+ v2 w' T: t5 W9 Q- o
以上我精簡了一些 也能跑模擬圖( d' N! ~$ e" m# Y7 x4 q+ t
但現在重點是我該怎寫60→59→58...
! Z& l, @% r G W% `: J7 V初始值60要怎寫...
5 d2 ^( H8 l: x% v! o是要多2個input 然後給他一開始的值?" `! Q, `% o, F& L W
但要怎寫啊@@...
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