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Key function. z! {, Q8 Q# ]* ~7 J$ o" \0 W
按鍵開關 第一次 on時,開始計時。
; p) o( r: [ ^* W) `3 d4 E 第二次 on時,停止計時。
3 x% u1 j- Z: n3 t3 s( D 第三次 on時,開始計時。& s$ K5 u* L* _$ U
未 synthesis,請自行 debug........ 7 D" D2 D* M8 B$ I. g* I' k$ _
/ f( a$ x8 n) ] t' J/ j+ \LIBRARY ieee; % l* N, ^8 T, n' g4 n/ n
USE ieee.std_logic_1164.all;- s9 r6 j& @. p7 R: I' e9 G
USE ieee.std_logic_unsigned.all;, A3 x; H" B0 c: O2 o( {
ENTITY KeyFunction IS
5 L& U" }; R! Y, S PORT(CLK,1 L0 R; v, Z0 k4 }
PB,* u3 V$ R8 f% n
RSTn : IN STD_LOGIC;
" b+ s* Q6 P: [+ ~5 \ START_COUNT,3 J% c( o% [! J/ t( N' h
PAUSE5 y) N2 q9 [9 d
: OUT STD_LOGIC
4 X: w& x- c4 f );
! u3 b5 p5 `7 ^# j! r! |* {# fEND KeyFunction;, Q' w% C8 x" a) _- {
ARCHITECTURE arc OF debounce_v IS5 T% }9 }; g+ H
SIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
5 |& @, a" q K% Hsignal pb_reg,debounce_counting,debounce_end : std_logic;
?8 t) h5 q; U8 h. [1 Osignal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);
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constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";
. N0 r5 H+ L9 w5 ], y2 CBEGIN
& ~" U2 `( e0 b X
/ M8 D" U2 Y8 S( U) Z8 ?--============================================================( E$ A( |* x; G2 x8 M9 o; z
-- get key push state. ( active high)9 `/ i9 }% y3 `/ q3 N9 ?
--============================================================
. K& h5 N o% k; s2 P PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)& X& ?7 z5 E) h3 r4 b5 C: _
BEGIN @/ |. G' i+ L0 G+ u& S
if( RSTn = '0') then# E/ \0 I+ I( m" e' Z H
pb_reg <= 1;3 K: U7 q! P- ?) ~: m) \4 Y3 C7 l
elsif( CLK 'event and CLK ='1')then6 ~6 o' ]" {+ Z- T9 {) d+ S* T) O
if( PB='1' and pb_reg ='0')then
" Q0 @! }% @, v( i debounce_counting <= '1';
% E, I( x% t: N! v7 x" X) [ elsif( debounce_end = '1')then5 U) ]7 V" i: c) d: s
debounce_counting <= '0';
. R( P- j v5 R7 ^+ B& N: { else# b# ]( H M0 g+ n0 @
debounce_counting <= debounce_counting;
# ^. |/ Y' n" ?" x' G" o& m end if;. ~7 G+ v: x5 U; @( K0 s3 \6 F
pb_reg <= PB; 4 R' E6 G) }) M3 m; N( l# [# S0 h& |1 ^
end if; |
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