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Key function2 O5 Y: a2 V `/ ?7 d" g2 H$ C
按鍵開關 第一次 on時,開始計時。- O5 A r7 d, a+ I9 d" f1 ]* Z
第二次 on時,停止計時。; O2 N8 ?9 T! q2 \2 s
第三次 on時,開始計時。0 p4 e, P6 O5 k" y' @* t6 O+ q
未 synthesis,請自行 debug........ " m0 u7 j" m" p* t3 g, W$ t8 [
( B$ I% f4 ~* F6 C: O& T+ g7 u0 pLIBRARY ieee; ; d/ N3 ^3 A. s0 V" p/ `
USE ieee.std_logic_1164.all;: t8 z# s! t3 q9 \# H8 @
USE ieee.std_logic_unsigned.all;
0 L3 h' a& c' @( ^) c0 g4 ?ENTITY KeyFunction IS
4 ]" |' M m4 r PORT(CLK,3 s" x1 d8 P3 E
PB," H$ i3 t8 v l
RSTn : IN STD_LOGIC;. ?) F- G" Z0 y9 Q( j: Z0 `
START_COUNT,4 U. B9 M4 p4 ^$ }8 a; S
PAUSE
# ]. a U$ C! v8 v6 o2 {7 c : OUT STD_LOGIC 2 v0 d% B% w ]+ n' q% u' i: O0 e2 ^
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END KeyFunction;
- f: ^$ d6 C5 {, L: P4 SARCHITECTURE arc OF debounce_v IS
6 O; A, s7 V2 }3 s: cSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
" y8 E6 E% m; ~7 p3 f! Gsignal pb_reg,debounce_counting,debounce_end : std_logic;
- h+ z/ Q0 _! ~7 Isignal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);. a% V6 h) @. ?5 a
$ }6 a( w+ Y( H) e/ S% |constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";- m4 `( H9 z4 a, _3 L
BEGIN
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0 `; f" t* g' [2 x: j' U7 @--============================================================
- b& a& a3 b+ ^/ h: W: \* ]: p-- get key push state. ( active high)( p7 N% Z: a& F; e n8 |; B* t9 W
--============================================================3 J+ B1 S. R4 O$ S# a; g
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)+ @) p4 i' A7 |$ U
BEGIN% ^9 h" x2 C( @" o
if( RSTn = '0') then
: Z" l) J$ l: R& i2 b g5 w pb_reg <= 1;' H7 T( c1 e* E, ~5 e+ m$ `/ o( D! d) R
elsif( CLK 'event and CLK ='1')then8 q7 h; ? k/ i' E! C% Z) f) d* U
if( PB='1' and pb_reg ='0')then
6 L9 ~5 Y7 a0 f5 t) _" N debounce_counting <= '1';! h; x, r7 M' p, w. W! L8 t6 Q
elsif( debounce_end = '1')then4 F5 q& s! C% K9 S! q
debounce_counting <= '0'; . K& m: {/ j, f+ o' l/ a
else
3 a& p, _' s6 f& u debounce_counting <= debounce_counting;0 |5 m1 @ e& Q _
end if;
' s) q1 o. R& K* }9 V pb_reg <= PB; 9 `* \9 r6 f% Y# j! ^) ~, Y
end if; |
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