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下面分別是我寫的除頻器及它的激勵源: {6 i/ b3 V4 U: y% y S5 M
但我使用modelsim時卻無法正確的讓它產生振盪) d6 g, F. k+ c+ Z" H5 ?
該波形完全處於0狀態" O' i+ f1 a+ C) J" f1 V {
但實際用fpga燒入以視波器測卻可測得其波形3 Z' j+ U7 Z( }1 H
不知道是modelsim本身看不懂我寫的+ x9 `! j' D* @( F
還是我根本就寫錯了
6 Z0 H6 U2 `- x/ g( D# T; R又或者是testbench沒寫好?
. t B. s4 Q* F- I* x9 n煩請各位大老多多賜教!!
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module F40M20M20k50(F40M, Rst, F20k);
- a z! B& [( o3 N$ r input F40M;
, ?3 q) h0 y& R: T9 D* H- Q input Rst;
" E6 @3 i, \, [, a. v; c! ? output F20k;
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% }7 a* K3 y/ Q# \
reg F20k;
: y3 |# |9 e+ p reg [10:0]B2000;
. e9 p! g, S3 d) T reg Count;
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) s5 H9 y1 O2 u( Y5 p& L4 c6 Oalways@(posedge F40M)9 J7 [6 M$ h3 d5 E/ O; V, @
begin+ n& m3 ]- ]/ v- x0 t6 g9 s
if (Rst)
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B2000 = 0; # _; E5 x$ o @
Count = 1; " [8 N; `8 c; ^6 J( u1 b5 D ^
end) j: I4 t1 w D7 a8 L z
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else
6 @1 J+ N: S; S# k& k) j' k+ w begin
$ O u+ ]+ d6 B* Q. X if (B2000 == 2000)
0 Y; e# P+ X! G+ Q6 \ begin
& x3 x [; D6 z+ t F20k = ~F20k; : f4 f0 S4 T" L0 `
B2000 = 0;
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else7 H! {$ h3 t' o: ]1 J- m
begin
U ^) R7 W1 z, U B2000 = B2000 + 1; : Y J: |" Y/ k f/ C# N
end* T* J. e6 ^/ C5 O# d
end
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, k& n# v, d5 O( n7 }7 X end
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$ T; i" V; d2 w4 B ?" `. S% n: yendmodule2 C3 ]4 Q# S; u, y, G) @# D
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--------------------------------------------------------------------------- V" l+ q5 `5 }7 ]! \8 d
`timescale 1ns/1ns+ q! O" M8 ?& r3 @$ N
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module testbench; t0 N& N( s, B9 _
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reg F40M;: N" h% d" @& T b$ j% r, M
reg Rst;
3 `1 u0 N1 p, ^' I3 [2 }3 owire F20k;$ k% ^2 `! K3 o# v
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F40M20M20k50 ReiRong (.F40M(F40M), .Rst(Rst), .F20k(F20k) );
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initial $monitor($time, "F40M = %b, Rst = %b", F40M, Rst );
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$ q5 A' b7 W6 \4 t; b0 Y& Ninitial begin+ \2 k# ~* f) E! C) x
9 l1 Q. s4 X8 c6 A F40M = 0;8 ~ w+ c6 P6 E3 l. m
Rst = 1;
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end9 T: i- y6 F3 m
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always #25 F40M = ~F40M;
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#100; w1 X5 K5 t; l
Rst = 0; 1 o/ y* H) A- Z( p: o$ H
end/ i" y1 o. k% h, B' z: `0 I
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endmodule |
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