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發表於 2012-6-18 18:27:33
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顯示全部樓層
我也來寫一個/ e+ _4 ~* Q- r/ d9 o1 y2 k- o
輸入:clk, rst
, h7 x6 {4 s* J& Y. Z3 W5 p輸出:tens(十位數), units(個位數)) T [: g. B- N/ p! \
+ t; f0 V! M. |; K0 L: v: Y8 Q$ q6 jcode :
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module BCD(clk, rst, tens, units);8 {; z4 y, @# g) j' _5 q2 _
input clk, rst;
+ m4 B9 b2 H- w. ^ output [2:0] tens;$ ?' y% N3 h/ t8 {
output [3:0] units;
& Z0 x; v2 w: i. J9 v% u reg [2:0] tens, xtens;0 Y: }! T. q6 S* [
reg [3:0] units, xunits;! ~' f+ Z" D* L( _: [7 [0 H8 v! f
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always@(posedge clk or posedge rst)1 d# Y' x' U' z, x" y
begin
, B4 U$ q" i% R& _, }1 y* u3 b if(rst). E% Z7 S. V' U" ^
begin
; K' v" _3 `/ U$ y1 d$ X7 W7 @ tens <= 3'b0;5 |/ B" n7 c) p" ]7 `! R
units <= 4'b0;
7 e$ W3 _; }8 f& Q end
+ D$ [+ c; b6 n& a else
- ]4 q' A6 H0 j, @8 j begin
* K" R& M8 H- ] tens <= xtens;
/ @7 g! O5 M$ U8 {: m6 P& d: p9 q1 F units <= xunits;2 _. K4 k' j$ Y q
end
- k3 ^# q8 |( t* [! M3 {" z8 r end: g7 q( q+ ^: K# d$ R) o( _& M, ]
6 d% Q$ [) H+ C/ Z% O; D5 V always@(tens or units): s" B0 c( R- U4 E8 O
begin# a3 S1 @( |, F2 V7 J
if(units == 4'd9)
/ C% [" p. ]9 q begin
# v" t7 {) f" @' F0 a xunits = 4'b0;# |6 a& }1 f8 q& T5 z
xtens = tens + 1;4 F6 o4 n3 n: C; A) b
if(tens > 3'd5)
% K4 ~, K+ t; z; C7 O xtens = 3'b0;
z& @' D' b, Q: [! i) C+ s else
# G: C1 q) j1 z3 E2 j xtens = tens;0 M9 T' T( E: C$ k; Q
end
9 D# H/ t/ H* V3 t4 [+ q$ g8 S+ ^# { else$ W- k3 ]5 @* [, @* a" R/ T
begin
+ H' z) [, Z5 Y q xunits = units + 1;
. S4 o: L+ F6 X% |& ?5 W& J9 l xtens = tens;, z, w, p8 u) C/ h4 T
end
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endmodule |
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