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下面分別是我寫的除頻器及它的激勵源
" e0 h. c [8 e; T但我使用modelsim時卻無法正確的讓它產生振盪
' I0 @$ g5 B" N8 I; d+ }" f; _$ z該波形完全處於0狀態
+ |( o+ s" ?4 g$ C3 _7 c& `& Y% ~但實際用fpga燒入以視波器測卻可測得其波形8 i; F+ E' T/ w; R( O
不知道是modelsim本身看不懂我寫的7 ~# e* s1 E% O8 x& A8 e0 u. j5 O
還是我根本就寫錯了# g2 D3 l0 B2 }- ^. U9 F
又或者是testbench沒寫好?
5 @1 I% u/ n1 T3 h煩請各位大老多多賜教!!
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4 {& Q. f; J4 g" S* cmodule F40M20M20k50(F40M, Rst, F20k);5 A& i- m, H% g3 K! \: O
input F40M;
" J( d" d: {9 |' M input Rst;) b- F( m4 Z; e/ ?
output F20k;
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) e% e5 j1 F# q! r V2 { reg F20k;5 x. ~- @' D9 W- v
reg [10:0]B2000;8 X9 O4 ?* L* W3 n& H. d w
reg Count;) _+ K! W2 p. F3 p, f
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always@(posedge F40M)
4 e3 O7 I9 [$ |5 \# ubegin
6 o) v- t& R) _ Aif (Rst) - B' e$ C; I) x
begin
/ q1 h! k* ?, v8 P0 B B2000 = 0;
1 O" A) s" J$ j7 R4 r7 w Count = 1;
: D$ P4 |4 V) S$ T' O7 v, ` J end
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else ; E3 i' Z$ b6 X8 g6 j4 Z: B
begin
; j/ J" I! C( R& {& w if (B2000 == 2000)
1 W( F& A) L F& {- Y begin
. a9 A+ I8 d+ L6 I+ ~8 `3 t5 T F20k = ~F20k; _: n- b G% m$ f' x* s4 f6 K% d
B2000 = 0;
% Y: Q4 a% k- }3 ? end
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begin
% B( z' l. f' f B2000 = B2000 + 1; 7 t! ^& j# F4 R3 q+ B+ H
end
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end
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$ G; p: N5 C( m+ m; Kendmodule
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---------------------------------------------------------------------------
* H: W& p- K. m1 \+ i" O`timescale 1ns/1ns# K8 j& P8 q, s3 _# p J
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module testbench;
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! `% x/ t( K$ K4 b# x4 q' \reg F40M;* R5 @. h8 a, c& L/ y' s9 R
reg Rst;8 Y+ i* F# n* M/ f5 F1 I2 l/ B* |
wire F20k;0 \( i& K) E' d- w) j
, Z" }4 b- x2 Z' X' D F40M20M20k50 ReiRong (.F40M(F40M), .Rst(Rst), .F20k(F20k) );2 {# x( ^" y1 |: f
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initial $monitor($time, "F40M = %b, Rst = %b", F40M, Rst );. t c: v$ N7 w2 O; o
) l; V4 M" @! ~! b$ O5 minitial begin
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& U: F/ x- u! P( U F40M = 0;
, N; d: E- Z. _* [: N q Rst = 1;9 w. b- n8 X# S) z% |
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end! ]9 C r7 Y7 ^- ?4 O9 | f/ r
% a0 M- u# C) D! i ^' F2 v5 d always #25 F40M = ~F40M;3 Y7 m" e; i7 l$ t9 u2 z
initial
" G& }/ [$ s" I& r0 n) n9 b+ i begin 1 m5 `' y6 Q5 N0 a6 a
#100
! s4 K$ D0 w" H# `! n) ?2 E+ y6 C Rst = 0; 3 u/ a1 C" M# P( R- M; b& G" p: r
end" ]* N z R# [! b
5 z: p. A3 `0 f6 J3 Qendmodule |
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