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Key function4 P1 h% }4 Q8 m/ r
按鍵開關 第一次 on時,開始計時。# T- }: q3 S, i
第二次 on時,停止計時。
+ k Y8 V* [+ Z/ r 第三次 on時,開始計時。
7 U% r1 a3 u$ Q: a+ u未 synthesis,請自行 debug........ * L: F/ P% ? H
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LIBRARY ieee; ( [) H. w# y4 d, u a
USE ieee.std_logic_1164.all;! t0 o( }1 q0 q
USE ieee.std_logic_unsigned.all;
" l9 Q5 y$ d# v F. ?ENTITY KeyFunction IS* t4 m' g) p: m4 y* j; s1 t
PORT(CLK,
" [7 P# ~3 |1 k, U- Y9 }* j. J PB,
6 H' u1 A8 v! _6 r; U RSTn : IN STD_LOGIC;* S& S7 Q% h6 g4 S2 x0 y* o2 h
START_COUNT,2 K- Q4 v! w2 B5 c
PAUSE2 c" ]- t- @4 I! {% X9 f z
: OUT STD_LOGIC 1 o& p+ J2 f7 N# s
);
- Z Q( S1 f; ^3 n2 I, A5 _END KeyFunction;
7 a1 p0 ~6 O2 u1 i* [& @. }8 vARCHITECTURE arc OF debounce_v IS
0 J/ J( q: c, PSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
% U F# m: b- H. W" `signal pb_reg,debounce_counting,debounce_end : std_logic;$ C: @+ V; Y0 y) o3 _
signal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);
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constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";8 V P; W2 ~( Q. t+ }
BEGIN
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--============================================================. Y! |" B- p; O* j+ h3 o
-- get key push state. ( active high)
( b* H. ^7 L. l% |( g& W--============================================================1 [* U# G& A- Y5 h
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)7 w3 _( o- v9 ~) k
BEGIN6 L/ C8 |! Y9 m8 e3 _5 Z
if( RSTn = '0') then) @1 u& ]+ @) _( T C. f
pb_reg <= 1;9 u# t& |) _7 O* ~& k8 h& M
elsif( CLK 'event and CLK ='1')then; r1 \& T$ ~, X& V: E
if( PB='1' and pb_reg ='0')then
6 O3 }- j( E e5 J7 m- L$ }6 P( o debounce_counting <= '1';
6 M2 d( D3 O7 ~8 k* @ elsif( debounce_end = '1')then) ^% L' F) y5 e' F$ {
debounce_counting <= '0'; " C" h$ h `6 n" v
else
; ~6 v% W+ j) Z+ S/ l debounce_counting <= debounce_counting;, A' h' u. Z- _& `( r8 G
end if;- w0 |5 ^" J# {. o# r
pb_reg <= PB; 3 o% E; c2 v1 [! I- j: E. V9 m1 R8 {$ ^
end if; |
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