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Key function9 c* q1 ]: q4 p2 o
按鍵開關 第一次 on時,開始計時。3 q$ F# p0 ^& }& m* Y
第二次 on時,停止計時。) B, P* Y' n& b+ I. m" p2 p
第三次 on時,開始計時。
0 H! W4 N8 ?' j8 [8 R未 synthesis,請自行 debug........
% g& ^4 f$ {4 k9 l- y: Y) o& i: X! I8 j
LIBRARY ieee; 3 a) l2 R( t+ X: J7 e) v
USE ieee.std_logic_1164.all;
) E/ n" A/ b. ~( N& {1 cUSE ieee.std_logic_unsigned.all;+ p( a$ H( H! H- k4 p, q9 E; v5 X M
ENTITY KeyFunction IS
3 y+ L. K: x0 Q0 K5 U" Y' w; Q9 j PORT(CLK,8 Y/ m- V1 ^0 _# y0 s7 K' B
PB,
3 Y7 u# @( }6 C4 A) k RSTn : IN STD_LOGIC;7 b3 u. J" x H4 `5 J
START_COUNT,5 M% `0 j/ ]8 k8 E- O$ i
PAUSE
4 k. C! m6 f" ~' `7 h' Q- I : OUT STD_LOGIC
1 [+ B! i5 `" _& ~; L. c );
" M/ L, s0 S' S2 DEND KeyFunction;
% S4 y7 j0 Z% Z, aARCHITECTURE arc OF debounce_v IS
S# A3 i& R& ~7 H- o: {$ FSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
! X4 |! X7 v' Z* L: k& esignal pb_reg,debounce_counting,debounce_end : std_logic;2 E8 }4 N% ^( b% ?2 u
signal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);$ s. c- W4 N: y" x0 B1 _
% ]# @' Q; f1 t3 gconstant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";
6 ~9 ~) l- h7 T1 s8 h4 h1 y9 R4 {BEGIN, w3 q- n' g; `/ j
, e8 e7 O& v* l--============================================================
; F! Z; g& L) V% u7 ]- k-- get key push state. ( active high)
2 U, v9 A. k9 c--============================================================+ t8 D0 C9 Y0 \4 O
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)
* d; e" m- T- b0 }- \, X) J, T BEGIN- m. R Q4 Y) n3 J
if( RSTn = '0') then+ r2 _7 o2 O2 v+ f
pb_reg <= 1;0 C7 }7 M7 Y# g! R( o
elsif( CLK 'event and CLK ='1')then
9 x1 R2 F C d- g2 c. t; n if( PB='1' and pb_reg ='0')then
9 a4 }8 W! Q, L. I& E* ] debounce_counting <= '1';
, H; A% M& N, k# s3 j/ B elsif( debounce_end = '1')then# J! p1 ]! @5 J9 E3 l; d+ v3 t
debounce_counting <= '0'; - n8 u+ ~- v9 ^ g& }7 V$ o
else! T3 C1 ~# ~" W. W9 s6 m1 t
debounce_counting <= debounce_counting;
$ l9 w% [- z3 P- o end if;4 g3 K2 `. L# D0 w
pb_reg <= PB;
9 b$ r7 |! _* C end if; |
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