TA的每日心情 | 擦汗 2020-1-14 15:59 |
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签到天数: 1 天 [LV.1]初来乍到
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发表于 2008-12-11 20:36
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`timescale 1ns / 1ps* w) m2 v5 E/ h( t
module GreyCounter
: k: D7 V3 [, d3 x# N; @(
+ V! g( P, z5 d9 N* t // outputs:" t' O+ B! ^# {% I) A( M
greycount,; j4 n# o( c. S' N# ~ h0 T* v' p
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// inputs:" t. n$ J- K) v" X
clk,
, Y; i( o7 o$ a, Q6 f9 D* L' } _ reset_n,% @5 g% Q( j2 `" f& E2 l
en, T0 w$ c; S0 B) ]
clr. \+ `: R& O- n6 h$ A- d0 b
);8 |6 f* A9 m3 Z# A& z0 ^7 O
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parameter WIDTH = 8;
* T7 L- k) }. E1 o- nparameter DLY = 1;
, G7 h* q( I# U' z
$ J; g6 c0 W% w6 i& ^. ? Uoutput [WIDTH-1:0] greycount;) h& i& Y, h8 W0 y: Z
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input clk;3 ]3 \' B& Z/ A% H3 f# |: k* Z
input reset_n;
9 Z+ T9 F4 o2 p( P. winput en;
4 I6 I; {7 ^! o0 D2 e3 ]3 zinput clr;/ _5 r, H+ ]1 p5 I9 L
1 S4 U* A4 M e) Treg [WIDTH-1:0] greycount;
/ M/ X, L( g1 A: q& C j( I# breg [WIDTH-1:0] bincount;
5 K. d& H) z4 z+ J2 yinteger i;/ y& i0 ?+ P, k0 y- G8 T+ B; x
J! L7 N1 L/ h0 ialways @(posedge clk)1 H1 x% n/ Y) m' V9 u* N
begin/ m9 x- @8 x7 u3 ~. g$ Q
if (~reset_n). G7 @2 j7 C. @8 k2 s
bincount <= #DLY 0;
/ `! v- I6 W1 Y1 @ else if (clr)
: U$ s. K$ |% e bincount <= #DLY 0;" f9 e6 x/ Z! W: h( x( p
else if (en) & d& }, ]2 Y0 {# ~2 T5 ~
bincount <= #DLY bincount + 1'b1;
( e% r2 J9 |& D' b4 y else) O$ ]9 @/ b N1 u$ P' F
bincount <= #DLY bincount;# C4 m1 h* C8 S. F; w. t& \
end* j0 m$ Q4 ~/ i9 K$ U
+ a6 R# a: J! O7 g: f
always @(posedge clk)
# d) E# ^9 L4 N! ^& ?* ]1 Qbegin
1 B* o) z5 t: l# _( G1 f if (~reset_n)
' K5 [; h! u+ `' [, t' @ greycount <= #DLY 0;
0 |% B. O, V1 S else8 x* s+ K) x+ m8 n" g( w
begin# N3 H6 m4 O: v# A+ ~; h3 l. ^
greycount[WIDTH-1] <= #DLY bincount[WIDTH-1];$ ]* K6 k/ _! g" Q# A, P% j6 |6 |/ }
for (i=WIDTH-2; i>=0; i=i-1)" [2 T+ \% u& [0 E: Y- a' ~) C6 W
begin
- v9 z$ ^( N; O6 G" T8 i; o greycount <= #DLY bincount ^ bincount[i+1];- U- S) _0 t7 t' D) q, c# Y
end
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end' ^3 ~' s5 U1 g8 m' O/ S# U7 @: {% A
0 R) [9 V3 w4 T9 O4 xendmodule5 L- o& S0 r* G3 Y% Y9 Z; S
+ u' \' O: u5 P' B) ?
貌似上面的只能用于激励仿真吧5 s& D& r* `' F) z0 A# w6 K
for循环 ~~! |
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