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请问其中ASIZE为什么是4?我觉得应该是3.我在一本书上看到也是4.
9 d( M9 f, F$ x* {4 F2 smodule fifo1(rdata, wfull, rempty, wdata, winc, wclk, wrst_n,rinc, rclk, rrst_n); & P- I& Q& ]9 R- I* C+ X# I* z% u# `9 g2 p
parameter DSIZE = 8; parameter ASIZE = 4; S6 M. G) Z5 H2 _; P" i' N4 O
output [DSIZE-1:0] rdata;
* D6 Q0 {5 m8 w7 w' I. eoutput wfull; 7 A+ N' N1 @& E9 j9 _# {$ u5 b. g
output rempty; % F6 v& j/ C. |" c, O
input [DSIZE-1:0] wdata;
, Q9 K1 I4 q' J9 \input winc, wclk, wrst_n; 7 M: K( R8 G, m' |+ l
input rinc, rclk, rrst_n;
& p% ?9 T1 D F+ A6 oreg wfull,rempty;
: R- Z9 o" A3 ^) |+ \# oreg [ASIZE:0] wptr, rptr, wq2_rptr, rq2_wptr, wq1_rptr,rq1_wptr;
9 `8 u/ v3 s0 L( Y: p# N: C: d$ R4 Preg [ASIZE:0] rbin, wbin; . W0 m" N+ R2 w+ A# D1 s
reg [DSIZE-1:0] mem[0: (1<<ASIZE)-1]; ! F6 @, s+ q) W' g; v4 z/ B+ ^5 A
wire [ASIZE-1:0] waddr, raddr;
$ U" |# w/ O, V t+ ~% W3 Uwire [ASIZE:0] rgraynext, rbinnext,wgraynext,wbinnext;
4 g; V/ Q( O$ B: Z" w# N: V; Uwire rempty_val,wfull_val; 7 H- b2 X1 |. _1 V7 o& h3 O: T
! U5 W5 |, b; ?8 T7 E9 g/ l
assign rdata=mem[raddr];
4 N' d! E' V. F' |, f% G3 o5 }always@(posedge wclk)
9 d& _+ [; b# a3 [. w V+ bif (winc && !wfull) mem[waddr] <= wdata; 3 @( T7 A) e \; P9 o
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always @(posedge wclk or negedge wrst_n) 3 L4 E4 W, Y8 n6 Q
if (!wrst_n) {wq2_rptr,wq1_rptr} <= 0; " V2 e- ~* f* n6 ?
else {wq2_rptr,wq1_rptr} <= {wq1_rptr,rptr};
4 [- N" n1 g) S) g, t) q- a& M6 Q: E6 j
always @(posedge rclk or negedge rrst_n)
8 f7 G, M% @% [' tif (!rrst_n) {rq2_wptr,rq1_wptr} <= 0; 5 z, w. |$ V) X) H* ?- }
else {rq2_wptr,rq1_wptr} <= {rq1_wptr,wptr};
! a/ f+ I6 l b
: U0 ~! w, f: _0 Z
8 ^ P6 K' r) P1 Q9 ~always @(posedge rclk or negedge rrst_n) // GRAYSTYLE2 pointer
5 z0 g6 _) b' `& `9 S0 vbegin
8 G. y' z$ y! ?. Q" V1 d+ G; mif (!rrst_n) {rbin, rptr} <= 0; & c4 a$ y) X8 t8 p
else {rbin, rptr} <= {rbinnext, rgraynext};
5 i. l3 t* h- b/ `end
9 m- l$ J5 R+ e+ F& P D1 J4 T( Z. L' d
% Z* n/ I. f9 e+ X/ K8 l- u9 q1 U. _
assign raddr = rbin[ASIZE-1:0];
2 U7 \9 N- G# v; `3 M4 a( F8 A$ g/ L) D. Iassign rbinnext = rbin + (rinc & ~rempty);
, Y- ]$ G S* F$ m, E: b- gassign rgraynext = (rbinnext>>1) ^ rbinnext; ! s$ H7 A6 u1 T- L2 ]3 T$ U
* j* P9 J$ p5 A3 r7 @: f, P2 X, I! V5 X1 U' ~, ?$ U
assign rempty_val = (rgraynext == rq2_wptr); 0 s+ L% k: O9 n: [' `; d
always @(posedge rclk or negedge rrst_n) 0 l& ~$ ~% h3 E3 l& K4 M. T2 u/ y4 A
begin
/ G0 s8 D* w/ \$ \8 nif (!rrst_n) rempty <= 1'b1; 4 o* z9 n7 t! V4 B" Z
else rempty <= rempty_val;
}5 n6 \8 M# e/ K# ^end ' d; O$ P' T, E4 z7 K* B1 i
4 I6 Q5 [% q) r& E. S! P# E1 X: F
7 ?+ q! A3 @% C; c% g* Talways @(posedge wclk or negedge wrst_n) // GRAYSTYLE2 pointer & k4 U: f \. B& ~/ \5 a/ R" I! h7 D
if (!wrst_n) {wbin, wptr} <= 0;
! q L J/ X8 y' y0 p) Velse {wbin, wptr} <= {wbinnext, wgraynext}; 2 b3 q. D7 z( K
2 ^ i+ m- Y& a# D1 e
# L5 L. h! P. n$ Zassign waddr = wbin[ASIZE-1:0]; _* U: s$ {) k9 C# _
assign wbinnext = wbin + (winc & ~wfull); ' I/ x" @7 i! e* v* S
assign wgraynext = (wbinnext>>1) ^ wbinnext; 3 O/ J$ X* m2 E' K
assign wfull_val = (wgraynext=={~wq2_rptr[ASIZE:ASIZE-1], wq2_rptr[ASIZE-2:0]}); //:ASIZE-1]
s6 i( x; s9 d1 [4 u0 d' T- ]always @(posedge wclk or negedge wrst_n) 1 h* H5 N) t! a
if (!wrst_n) wfull <= 1'b0; " l/ G! h* R9 B) j+ ]
else wfull <= wfull_val;
9 G5 b5 Z7 q9 E* d7 O; Gendmodule
) C+ E' c2 l+ d0 C. h; {1 P' p' y/ \9 ]
[ 本帖最後由 xuduo6845 於 2009-9-4 11:25 AM 編輯 ] |
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