|
Key function, `. z2 }1 B4 D; J1 p$ l9 V
按鍵開關 第一次 on時,開始計時。
' c; u8 p( H) m) V" @ u 第二次 on時,停止計時。
; v, Y; v8 R# c0 I4 i4 x& N 第三次 on時,開始計時。5 @# K5 m% T6 Y) u8 C1 L7 c' k
未 synthesis,請自行 debug........
6 |) z5 B& J9 ]3 c1 M
. Z2 r f7 Z! |; GLIBRARY ieee; ) `/ w: u* k3 c. V( R
USE ieee.std_logic_1164.all;) A: S$ o. s0 `1 u
USE ieee.std_logic_unsigned.all;
1 e$ ?( w2 X' k2 ?ENTITY KeyFunction IS
0 }4 q/ K# |1 [0 F* g PORT(CLK,# V- M! w. B9 \* p! L* ] Q
PB,. w8 R+ l" A# {$ j
RSTn : IN STD_LOGIC;4 C. D" P- K3 h! q3 }
START_COUNT,
9 j7 M. ]) ]! v2 D- j PAUSE; C6 W. U! U- w9 h Q9 _- a8 b4 v. D
: OUT STD_LOGIC
3 S0 r ~7 F( t/ Z );4 j M K' N% P
END KeyFunction;# B0 P6 h4 `6 |9 d/ v( Q4 W4 w
ARCHITECTURE arc OF debounce_v IS* `% M; z( w1 D* f8 |
SIGNAL currently_state : STD_LOGIC_VECTOR(2 downto 0);
0 B3 [# a1 N* l4 K U* @/ i5 tsignal pb_reg,debounce_counting,debounce_end : std_logic; [; \% v( ^4 b6 c: ?
signal debounce_counter : STD_LOGIC_VECTOR(15 downto 0);% G$ n( z. e! b8 M/ k2 s
3 N7 j; {$ E/ O; H! f ]; v
constant debounce_time : STD_LOGIC_VECTOR(15 downto 0):= "0000000000000000";
# U- s) |' j! c# r9 [+ R; L( U. QBEGIN+ f7 J4 R$ o6 _0 M# H
6 X5 f) f: I+ d) C! m* C9 _
--============================================================" n8 @8 b! a) L4 |5 T8 ?
-- get key push state. ( active high)
2 q; Z! ^! N" ^- _$ A6 Y K--============================================================
$ A+ U: _+ @/ g t* _ PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)
9 c' t9 `6 A1 U8 c. t+ t BEGIN) k/ A* \" a }! U u. g
if( RSTn = '0') then$ A |- V3 D O! A) r
pb_reg <= 1;
( c ^8 K$ J, e- n elsif( CLK 'event and CLK ='1')then) M" ~- X2 G! b+ ?( O8 \3 t; D, C
if( PB='1' and pb_reg ='0')then
3 q/ Q/ X: [0 X# N4 W debounce_counting <= '1';
1 U5 e3 j7 X9 ~& h- ?7 v elsif( debounce_end = '1')then- q3 @/ C! O0 e, A& I
debounce_counting <= '0';
8 X, B) h$ r! Z% W8 s else
# ?: ]4 C$ M) E g, g debounce_counting <= debounce_counting;
' @6 ~! K* D! [ end if;
0 `; l- u( }, @7 f( q8 [- d5 ~ pb_reg <= PB; 6 l1 `9 Q% P% f& a
end if; |
|