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Key function x4 J( Y. p2 D7 U
按鍵開關 第一次 on時,開始計時。
4 \/ [& {4 k: L: Q$ Q: j& d 第二次 on時,停止計時。* J) s8 Z# K0 T% h, f, o0 @
第三次 on時,開始計時。3 {. J$ b4 J& ?9 X' Q7 w; i
未 synthesis,請自行 debug........
+ C+ v5 m& P# T! a1 f# z0 ]% J- O2 Y# W `# \
LIBRARY ieee;
1 m$ X- \/ A1 I# [USE ieee.std_logic_1164.all;; m8 `' C1 {) O* a7 x3 d% s
USE ieee.std_logic_unsigned.all; G6 P9 h1 U" _! f
ENTITY KeyFunction IS
4 e0 U: ^+ N" y% c9 b PORT(CLK,$ F0 I5 t! q, O9 X7 @
PB,
( j4 e1 ^8 z- S, }4 T; H9 Y( { RSTn : IN STD_LOGIC;) J' v5 |0 k* f) }/ w% s+ ?
START_COUNT,
( o y4 d- X- D/ N) y. V PAUSE
! H: A$ n$ o; m8 j4 u : OUT STD_LOGIC 5 q) ]: e# s) T6 k- v* L% J' \& x
);
2 T- `4 g( q) I, tEND KeyFunction;
/ `$ a$ h0 i. c3 n% [' vARCHITECTURE arc OF debounce_v IS
, i1 ]! W! n; r1 n4 `+ a: p2 Y/ m9 OSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);2 V3 j* Q/ r' p
signal pb_reg,debounce_counting,debounce_end : std_logic;
% R4 O8 I w+ {! C+ X" Esignal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);5 i/ }' @7 G1 V8 i. y- m+ ~; _- q
( [! p `2 r9 x3 S6 u/ R, fconstant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";
$ Z! V; w* N5 l' _/ pBEGIN
3 e! i5 `# S/ X1 Q4 }
& V5 y( u/ ?) ^0 U! y--============================================================
9 h9 ^ }/ w2 Y# z* V-- get key push state. ( active high)
, t( A+ K+ [% X--============================================================+ ]+ x0 ~1 y) _( K8 A; @' E
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)
. O7 O& q7 v% n" G. ^7 D BEGIN" w! [) Z) X9 }7 }% A- ^
if( RSTn = '0') then
2 O s9 t- t( T0 P% J; Y pb_reg <= 1;
9 |% k3 U& q2 e/ C, p elsif( CLK 'event and CLK ='1')then
8 b+ x9 b- [9 \7 \ if( PB='1' and pb_reg ='0')then
. J# H- |; N( k$ ?# d1 h debounce_counting <= '1';
, U0 \+ D+ r- L! _7 | elsif( debounce_end = '1')then/ h6 m' t8 L+ y+ t
debounce_counting <= '0'; % O- ]/ x$ x3 p2 w) \3 R
else) a) @% B9 b" n) `
debounce_counting <= debounce_counting;
2 J! T+ k2 A! i h end if;
$ J: H( ^) r0 w2 L% ? pb_reg <= PB;
( R( K% B q1 Q end if; |
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