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Key function" ^; C- q, G2 r5 @0 M
按鍵開關 第一次 on時,開始計時。, R+ s2 _! G% m
第二次 on時,停止計時。2 K" y1 t5 ~) H5 Z) _& R" h$ J
第三次 on時,開始計時。
0 k$ {$ j1 L: h2 g0 Z% [+ C' T' H未 synthesis,請自行 debug........
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LIBRARY ieee; : N. x& _8 u1 y# M5 u
USE ieee.std_logic_1164.all;
1 L7 d+ r: K9 B5 }* mUSE ieee.std_logic_unsigned.all;
2 O* v% y* y4 {% ^% dENTITY KeyFunction IS
% p; d8 ]3 R# p9 O7 c0 G PORT(CLK,: t! J: X' o0 A
PB,
7 f( x1 Y( v# \0 u% r' v RSTn : IN STD_LOGIC;
# I: ?/ u5 o! [# x1 P ]& o START_COUNT,
4 f' q2 o4 ?3 K8 Q, v PAUSE
3 F) @* @& ] D: T : OUT STD_LOGIC
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END KeyFunction;6 u. W; p# s' ?" f" y* c
ARCHITECTURE arc OF debounce_v IS2 R; G) g: V" B( f/ n$ p4 W4 _
SIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
1 t' T6 c* g- N% Y$ Dsignal pb_reg,debounce_counting,debounce_end : std_logic;; P1 b: n7 A/ ]
signal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);
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constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";9 l0 A- y/ g: B4 H. _) P% w$ x1 _
BEGIN) X6 Q- ]4 X: \, {4 z: P$ J9 l
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--============================================================
; c0 b1 \% F5 m! a6 v" q-- get key push state. ( active high)5 P* z6 {# o* [7 z; k. l
--============================================================9 v4 c2 A9 s0 f' E
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)- ?4 m+ B9 Z% S) H
BEGIN/ {0 T+ L) {# F* ~9 f$ d; |, @" z
if( RSTn = '0') then
0 T+ q( `9 V& R6 ?7 k& l- Y2 d pb_reg <= 1;
4 |* ]% {4 O. U h/ l9 g elsif( CLK 'event and CLK ='1')then( V2 a0 H5 w8 N
if( PB='1' and pb_reg ='0')then# O$ Y3 w% X+ A8 Q3 a& \8 a+ F
debounce_counting <= '1';
( F2 [8 b5 ]9 }) r7 x elsif( debounce_end = '1')then+ J1 c; b4 h6 E9 h
debounce_counting <= '0'; % ^& m/ K( w( z. ?+ p- m Y( Y6 D
else- g) O. U" W( B
debounce_counting <= debounce_counting;
_3 J* s; ]% O4 a end if;5 n* J) V; `+ N1 S) w
pb_reg <= PB; : `: r( M- h/ \% e1 x( Q4 B& A9 Y
end if; |
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