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Key function
: I0 q$ r" A1 s3 s( S: Q: R( D按鍵開關 第一次 on時,開始計時。 s2 x" ] k( @: ?4 z
第二次 on時,停止計時。* G, K n) F5 | w- l _+ {1 g+ \
第三次 on時,開始計時。" n7 G* _! s R, R, f5 q# Z
未 synthesis,請自行 debug........
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" @+ S9 Q% o2 \LIBRARY ieee; 7 i ^. m+ C7 G: ]
USE ieee.std_logic_1164.all;% Z: T7 Z% w9 e3 i4 b3 ]( O7 b
USE ieee.std_logic_unsigned.all;
6 U6 ^2 I4 ~6 a! ^" G& VENTITY KeyFunction IS3 T3 [$ A2 r. U
PORT(CLK,
8 Q2 I0 q; w( \% r PB,
, T! R* [* x+ P6 n5 K/ A RSTn : IN STD_LOGIC;
4 r+ z8 D/ N, u! ^ START_COUNT,
; u7 E0 N: n4 ] \3 Q PAUSE
* A7 {3 v0 Q2 q5 z4 s" x/ Z : OUT STD_LOGIC
7 h3 ^5 R' D: W4 o );
! v2 C: c3 b9 P5 q* `END KeyFunction;
1 @3 o& T1 \ b: e$ h" f4 dARCHITECTURE arc OF debounce_v IS
! J6 e- d2 A- i( d5 e1 QSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0); \# ?/ Z: S C; V! g
signal pb_reg,debounce_counting,debounce_end : std_logic;
0 P9 D8 o' A- h+ usignal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);
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{# {4 V/ P, Rconstant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000"; Q# C; y9 B8 i( }/ g) F
BEGIN2 r7 J8 N9 W, t
0 V/ t$ p$ y% f4 I6 g; P--============================================================+ R8 u: R0 T! I2 D. u0 b! h3 |
-- get key push state. ( active high)
& ] R4 d7 {$ E# z" W/ z& I4 x--============================================================* q, f ]/ W' O3 q. ^+ W
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end): F3 Y, M7 o8 w# b- o7 E5 ~
BEGIN \7 v: ?: @7 `5 n7 k- ]2 G
if( RSTn = '0') then
- q. e( G, n3 t4 @ pb_reg <= 1;/ f s: B! i, ?) m" S: q* V5 _9 e
elsif( CLK 'event and CLK ='1')then
6 K2 ~/ N l7 H, l if( PB='1' and pb_reg ='0')then
7 d/ ^9 o. m3 P8 Z4 }8 Q debounce_counting <= '1';
- b/ C# A. h X6 j8 f elsif( debounce_end = '1')then
! w% l, k. Y$ [/ J5 u2 H debounce_counting <= '0'; " i( ?1 K/ n% d8 m* |0 X3 Y& E3 d/ f5 L
else
" V' s5 D; [, y4 J debounce_counting <= debounce_counting;
2 i5 W: o. ~+ C5 c end if;
6 ~5 N# c7 {4 F( N) w; s6 H7 { pb_reg <= PB;
* {6 G$ u+ C' i9 o0 }" ]! @( ] end if; |
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