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先给出代码+ P! T; B n/ ~4 Y3 L+ }) O# m' J; i
+ G5 S2 C5 M5 Y" D. Z) zmodule fsm (
4 o# E9 S# _# ]; V9 X: N. ^- C. N3 @ clk,
: L' A0 ~4 e Z* B( `- G5 ^% ]/ W( C rst_n,6 l; i ~ H' s
w_i,% Q% N' ?2 K( K' W' R; Y
z_o; k9 ^! a$ A/ e$ `& z% f$ \$ o3 D* F
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input clk;8 g/ n7 B+ u3 {
input rst_n;
9 q# a/ z, S) `6 winput w_i;
* I* I+ G7 U5 E0 q4 w8 J0 ^output z_o;
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9 u0 f0 N" w; B$ g7 _% F, Hparameter IDLE = 2'b00;" k: ?: |: U; t1 ]* z- R' m2 d, b
parameter S0 = 2'b01;
# o( X7 E* t! ]6 r8 s* @1 w0 @; Kparameter S1 = 2'b10;1 ], S4 G9 G! a# w- K# T J
# `" ]; t4 S2 C: T5 Treg [1:0] curr_state;% }, s( ]4 K5 [$ G: i
reg [1:0] next_state;
/ T7 W( y: V' Q/ J/ rreg z_o;4 r$ a8 l' Z6 d+ K
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// state reg0 e1 g! x. C; A) N7 F" A
always@(posedge clk or negedge rst_n)9 ^. a, o! M- x1 p( Y
if (~rst_n) curr_state <= IDLE;) E. t- V- x3 {2 v% }" F" f# c
else curr_state <= next_state; R6 `# }9 f2 p5 Y( g ^) H
: w* i8 ^: ^2 z1 G// next state logic
. e, y, H( f7 a& h1 s- O& Galways@(*)
- G+ H! @) ^1 I) E. z case (curr_state)3 B/ D% z) c2 K# e2 X/ M: P: j
IDLE : if (w_i) next_state = S0;. S) N+ o$ f1 V. a+ R5 J
else next_state = IDLE;- Z t2 M/ e: `7 P' a
S0 : if (w_i) next_state = S1;$ ?* b! O1 {" |' D! x0 x% p
else next_state = IDLE;0 r1 O* L4 z1 L# e: ^: Y' c0 `
S1 : if (w_i) next_state = S1;4 E' [# ?1 H. P$ s+ z: ]+ {
else next_state = IDLE;- F& j( _8 q3 X. n" T! O2 l+ X7 e
default : next_state = IDLE;8 _2 i$ M0 W$ U- ~" I, X
endcase " a6 B+ w& W U G |2 n7 `1 J
4 G9 t2 _5 B- l. R/ E// output logic3 e- R- I6 G( D, v/ E
always@(*)' x3 Z! ^1 f% a' ~- q* |
case (curr_state)
* ^* C3 r+ i7 ?/ V; s: r IDLE : z_o = 1'b0;
$ G- M3 T/ p+ F8 d S0 : z_o = 1'b0;
{' C! o3 z8 f- R) Z4 ] S1 : z_o = 1'b1;
7 u" \1 L7 {1 b8 y" [4 @0 Y default : z_o = 1'b0;; s" e0 ~, Q9 P F
endcase0 f. l' ^( p5 X/ t: i$ O+ P
6 S. u: M0 W- v# iendmodule `. D' q7 I7 \: e: A
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5 S/ m1 C9 j4 F6 a; I# }) S' W% R. ~! r' w5 e6 `6 n
然后是状态机的结构图:
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1 l. |# r4 z7 ]! r
然后再来一个时序图:
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6 ^2 h' y" a8 ^1 w) P7 s' P; Q7 g# P' x6 b. A6 L
可以发现状态机S0已被综合掉了。
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