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Key function; I! T6 r! U( B& n, ?* p, u3 \ g
按鍵開關 第一次 on時,開始計時。
+ k* r! Q7 Q' F+ m% d1 m 第二次 on時,停止計時。4 ^# w5 `8 _3 |; D! r' B, r
第三次 on時,開始計時。
0 q& D0 a* L$ N/ x# F" h未 synthesis,請自行 debug........
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LIBRARY ieee;
2 d3 t9 t6 g/ `9 oUSE ieee.std_logic_1164.all;
0 U8 | X$ l1 O% y# j+ xUSE ieee.std_logic_unsigned.all;6 M* B: G# }* \1 ^' k2 X
ENTITY KeyFunction IS0 O- \; a" O6 B0 s* c9 }
PORT(CLK,6 }+ c: s: d+ n! ?
PB,
8 A( V: L) h- Y# `' \/ Z2 i RSTn : IN STD_LOGIC;5 k% R- \# k, s
START_COUNT,
* U/ r) O) N& n* M" h PAUSE0 S; v, r' N/ c2 V7 f% W9 L x
: OUT STD_LOGIC ! Y7 G: R4 E U" m# {; i$ t" Q4 }
);
3 z, m' N9 O, w. r3 GEND KeyFunction;
/ z' J! W9 h2 w4 [$ zARCHITECTURE arc OF debounce_v IS
/ v) @# h C* Z8 G! E/ pSIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
6 u! z6 N x% G; e; a) |: k" ~! asignal pb_reg,debounce_counting,debounce_end : std_logic;
3 E/ I8 } E% {5 gsignal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);
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constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";
1 O4 w" }) _( G: B1 o7 E [* r9 dBEGIN
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$ b: a. m3 f7 o- G--============================================================
( @1 S$ F, z* _* Q/ y1 c$ V-- get key push state. ( active high)& r( r! y; I) x- k( Q; r
--============================================================5 {% c! U( J5 H% D r8 j! {, n
PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)& g& R; n" r& `/ N% l
BEGIN
4 n( b: R" ~. A h6 A) ?0 B( w" q if( RSTn = '0') then' o- F. S2 u2 Q) L/ [- n2 G
pb_reg <= 1;; D' [6 T# }8 n, n
elsif( CLK 'event and CLK ='1')then4 g) W9 c7 E, e( H/ o
if( PB='1' and pb_reg ='0')then& x, o- f0 x' C& Q" u
debounce_counting <= '1';
) D, v0 V% v4 ^ elsif( debounce_end = '1')then
2 A6 E; A1 s0 Z$ v3 b3 @ debounce_counting <= '0'; $ ?5 D# P: a+ ?" }3 K
else
& j) x' g% S; N! I5 i+ h/ K debounce_counting <= debounce_counting;
- e; u' Z, P1 s/ O end if;
3 i2 H9 D! w" {$ h pb_reg <= PB;
% g9 l* ?8 |1 `) }( z& i# x! ] end if; |
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