|
LIBRARY ieee;
# p8 _2 F% \) G bUSE ieee.std_logic_1164.all;
5 z. K( U- y& k3 d& H8 V7 y, sUSE ieee.std_logic_unsigned.all;" v0 Q1 X3 i9 H( x* `3 C k! y
ENTITY counter_backwards60_seg2 IS
: t, Q# C! M. t& t2 S: l PORT(Clk : IN STD_LOGIC; 5 n# q& j4 x5 W- R+ Q# y2 x, D
Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ;
. f; y$ ~& x+ L5 E/ x( ^' hEND counter_backwards60_seg2;
# M" m) J. [3 `+ O( VARCHITECTURE arc OF counter_backwards60_seg2 IS
% o. P/ Q8 y/ M3 ` BEGIN" }' v) `4 Q' c4 E5 X* n6 Y
PROCESS (Clk)3 i. n1 B8 _( R( S
VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);
) J8 ^6 `- m2 r; c ]: X; _$ z- W VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0); ! {$ j) U+ `7 \6 I0 n3 i6 s8 |
BEGIN
( C+ B) O! z5 S g" k# w& q5 \
9 s- u( r: H8 A( I" n IF (Clk'event AND Clk='1') THEN ! m, u' p) @" M, d
( o& G/ v; c0 a. g$ F
IF imper0 >"0000" THEN imper0 := imper0-1;0 C5 ^1 y" A5 m3 `+ z
ELSE imper0:="1001";5 Y. @/ Z3 m/ l, ^/ }. P9 E* c5 Y
IF imper1 >"0000" THEN imper1 := imper1-1;
. t3 L. O8 V$ r2 ?7 E- x ELSE imper1:="0101";
0 n s5 w% Y3 B. b# f2 n END IF;
: w0 I) o% x7 F1 ^% \ END IF;
* |) }2 j. N! y% w9 a0 W& b4 E; C END IF;
: x! w) N; [9 ~' X8 u Q0 <= imper0; Q1 <= imper1; ! R3 z F# B" R: P- Y0 M
END PROCESS ;
" w8 h9 J' s- }END arc;. `1 n' L2 @ n* N) |# P
以上我精簡了一些 也能跑模擬圖+ ?1 w) m2 C; P; L z1 K6 E
但現在重點是我該怎寫60→59→58...1 E% X) W1 n+ j# ]* q' ~
初始值60要怎寫...
C( P) P A8 g是要多2個input 然後給他一開始的值?
I/ k, ?0 [) y7 b3 U但要怎寫啊@@...
9 p9 x) Q% U' \3 x; Y |
|