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--============================================================
, e3 ^3 W" z- R6 G/ p6 x/ x-- key debounce timer; {8 n) m7 U0 T
--============================================================
$ E& a9 m1 `" Q' @# j9 Y; Y PROCESS (CLK,RSTn,PB,pb_reg,debounce_counting,debounce_end)
! w0 ?3 l. f1 f# u; F' z) `3 u- S; M BEGIN! r( u3 D# r$ A! a- f) b1 m! V
if( RSTn = '0') then/ D! j) u- j- L; o
debounce_end <= '0';+ y' B) N3 X* ^9 [
debounce_counter <= debounce_time;
- i( V) j; R4 d4 t2 x/ |# E elsif( CLK 'event and CLK ='1')then
5 N# C q1 Y! G$ {0 z" U if( debounce_counting ='1')then2 U2 C! `7 G# ~& _, d! C L! }
if( debounce_count = "1111111111111111")then9 }, p( S, U1 u
debounce_end <= '1';1 e" t( }4 ^6 c
debounce_counter <= debounce_time;
+ E7 N) t5 u" {4 E else
4 C" h9 j6 h; I: j. N0 w debounce_end <= '0';! I# B+ m) N+ r& D* L
debounce_count = debounce_count+1 ;
5 S# [) W: y, R5 t+ L end if; ) I" O6 ]0 s" s- F7 X3 A( C
end if; ( E9 o9 _) b- G C& z& ?- S$ j; D, p
end if;/ V C2 m! N* \; P: ~/ q0 N
+ X" Q% D; I6 l% g4 m% d Z
--============================================================9 _9 B5 L0 F8 `$ _
-- key function control
% z: s- U, O+ m; w, [& m/ a-- PAUSE -(key push)-> START_COUNT -(key push)-> PAUSE -(key push)-> START_COUNT
0 n! I+ I7 O6 A* G4 H7 Y5 A--============================================================ B% M x: h! H; y7 B
PROCESS (CLK,RSTn,pb_reg,debounce_end)& P6 v! \9 e: E& }% e$ T; Z" c
BEGIN
/ {( Y8 F; O) t if( RSTn = '0') then! `) c; w2 f9 N4 o( q" ~+ _2 H
currently_state <= "10"; -- pause
, i5 x* W! e9 I7 k( f$ J elsif( CLK 'event and CLK ='1')then
; J" `" b- o, ]' d if( debounce_end ='1' and pb_reg ='1')then! l3 Y. C W7 W; Y4 i! m" r6 G6 s
currently_state <= currently_state(0)& currently_state(1);
@& N7 M: f5 L, t6 o end if;
8 d: g" y, _8 }/ _! o0 a3 u/ D end if; - |1 Y% O9 \, w) {/ l
START_COUNT <= currently_state(0);/ I9 ^% q- n: w, @, l/ B+ I" ~; A
PAUSE <= currently_state(1);( s9 f; ?5 D, s T. ^
8 ~7 d7 j: _% C L# p
END PROCESS ;
" D9 @ a0 F: f# ]: l% mEND arc; |
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