|
LIBRARY ieee;
( Q7 \, V9 N9 W! n% O4 R/ \USE ieee.std_logic_1164.all;
" b, w4 A0 v, Y' z$ D# QUSE ieee.std_logic_unsigned.all;
) b* K; T, u5 k2 ]0 r5 E3 gENTITY counter_backwards60_seg2 IS2 z5 A- l7 k7 M6 {# L) W& t
PORT(Clrn,Load,Ena,Clk : IN STD_LOGIC;
, S6 E, [- n/ }# F3 e- v8 U( l Ring : OUT STD_LOGIC;
0 h$ n, R2 M4 J( z9 {9 H Q0,Q1 : OUT STD_LOGIC_VECTOR(3 downto 0)) ;
7 ?5 j# r+ v9 ]. w) K n/ [0 _END counter_backwards60_seg2;0 I6 }: E" Z9 k5 a
ARCHITECTURE arc OF counter_backwards60_seg2 IS
( }6 R! t( c8 n/ [ BEGIN: @% g) e8 i) @
PROCESS (Clk)
8 r" ?# z4 V1 w# z0 G; U0 A0 s VARIABLE imper0 :STD_LOGIC_VECTOR(3 downto 0);
; D* z# d; ]3 ^! s. E4 T* `3 G VARIABLE imper1 :STD_LOGIC_VECTOR(3 downto 0);
! H% R; m1 M3 `* D BEGIN( T( j% m* L9 ?: T& p8 ]6 W
IF Clrn='0' THEN imper1 := "0110"; imper0 := "0000";
& O1 h: H' b2 Y1 ^9 ? ELSE IF (Clk'event AND Clk='1') THEN
% | L$ X$ _1 V IF Load='0' THEN imper1:="0110"; imper0:="0000"; " b6 P/ k1 \1 g& K& [3 ^) p5 K* W
ELSIF Ena='1' THEN
7 ~3 f: }* {, v! u IF (imper0="1001" AND imper1="0101")THEN
+ c' D( i% }0 I1 G& R/ y imper0 :="1000"; 9 S1 ~; y0 O: C& ^. R
ELSIF imper0 >"0000" THEN imper0 := imper0-1;
1 u5 X' W# M0 a ELSE imper0:="1001";
0 G1 U6 e1 o: f8 @( t- d IF imper1 >"0000" THEN imper1 := imper1-1;
7 ^4 `' h$ J5 O ELSE imper1:="0101";
+ f5 l5 p3 o: F7 r8 B! v v) A2 B. w END IF;& \' \8 H6 d. b* `* D
END IF;
! H! b; a4 _* |9 @ END IF;
2 p7 g* i9 V6 w; r$ c, e3 h* O END IF;
3 X S- W, o2 u- z( X' W) w END IF; 0 v" n6 _0 ~5 _9 w( q6 O: e1 P# r
Q0 <= imper0; Q1 <= imper1;
6 L8 m* ?( T! C- V1 C; Z$ RRing <= not(imper0(0) or imper0(1) or imper0(2) or imper0(3) or imper1(0) or imper1(1) or imper1(2) or imper1(3)); t5 \) r; ]7 H* H9 R
END PROCESS ; Q% J/ z1 L/ j4 V, G6 I7 Y4 {
END arc;6 k+ O. [% M( n; s) {
5 ]- r( P2 P: B$ e9 O上面是我的倒數60秒程式
# r2 s+ X8 V% D' R8 e小弟不才
4 x! f" o7 D% M. ^ l不知道怎寫停止0 j5 r) F! S5 q5 g" ?
只要數1次60就好 |
|