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基于FPGA的hdmi sil9136 IIC通信设计 0 Z/ C, @0 b) }, j! Q7 d- S+ D8 u- \+ r( X
6 ~- n- E5 |7 ?1.接触IIC的人,网上都可以了解到IIC有着严格的时序图,IIC在传输过程中需要起始信号、停止信号、应答信号。' l3 I. \) V9 F- x; w0 }& |
: y/ l2 C* f' j& J7 y8 m; e开始信号:SCL 为高电平时,SDA 由高电平向低电平跳变。
+ O+ i' ^" Z. G: R5 [: i1 @" {2 h4 F! d% Y: y
2 o5 h# D' s1 Y: a
停止信号:SCL为高电平时,SDA由低电平向高电平跳变。
6 P/ C' a/ R3 S- z3 ]
& c1 `* M* @, h4 x: D, F3 m1 @ P. ?0 T7 {/ D+ o
应答信号:应答信号由接受设备产生,在 SCL 为高电平时,接受设备将 SDA 拉为低电) N$ {; y9 R. h# q
平表示传输正确,产生应答,否则为非应答, \; R; m* w/ a
) M' G9 F$ N0 Y; o$ P4 M( n( o
. \* \% N2 G$ D6 @! h f/ A. C2 `0 Z
# f* _" W. E( e+ u; h 4 t9 w( s6 z1 h0 M7 S2 a1 U3 [
% v( T& ]9 {0 k1 G- J" ]# X! Q' R2.下面基于fpga的IIC设计,该设计HMDI sil9136的IIC控制程序2 m6 X: Q9 V) A; S) [ T/ X
7 w. g% }! r, k$ lmodule sii_i2c_cfg(
8 t( n- O3 C- z input clk,; ~" \" a" w( Y3 X1 k: v
input rst,
- K, n3 g- B. @; z* M) W, o% Y input start,
+ g+ |- o* Q. A# s2 w0 w6 y output reg check_done,; _; w1 K& _3 @/ S% G$ S6 X
output [7:0]odata,. Q' n7 N- [" m7 H
output reg scl,1 x+ N7 L, s' u
inout sda/ W7 R9 @% K2 t0 g& g1 w6 u- k" p6 r
);- G* k0 _ ~3 @! L- `# r. a9 o
reg link_sda;
0 h9 D# a& u% J2 l# C$ {) o reg sda_buf;
! u- T% s9 O% n* f wire link_sda_o;7 A9 ~0 e2 s" z7 c/ ^2 n
wire sda_buf_o;
# O1 p6 I1 E( }3 E/ _ reg FF;" e% Q5 Y/ t. m7 T' Y6 N; t
reg [5:0]main_state;
) x: @) ~! H# T1 Q( K& h7 v reg [5:0]iic_state;5 a6 D' X0 ?$ m2 a8 d8 v3 L) f
reg [7:0]sh8out_buf;" [5 Y% h9 u7 X0 f% |' @( d
reg [3:0]cnt;: ?# W. G+ s# Z2 B: U3 Q
reg [7:0]rdata;2 z$ X) {' X' P, B
reg [10:0]time_cnt;
( G( g8 S" Q. b, C) N1 v7 ] reg [10:0]wait_cnt;- u- S' J" T. r1 m- p# J/ b+ `
assign odata=rdata;& H2 j6 b! ^$ D4 i4 h
. U4 h* s3 ~$ |. _! D/ D/ q
assign sda = (link_sda_o)?sda_buf_o:1'bz;$ T4 @3 N) K' i6 q% d* c+ s5 K
assign sda_buf_o=(sda_buf)?1'bz:1'b0;
) U* p( X" k4 y J1 @assign link_sda_o=(link_sda)?1'b1:1'b0;
# Y, c" e: q; U+ z3 U8 a//i2c scl6 ?% X c: @4 b/ U' q7 ~
always @(negedge clk or posedge rst)1 M( w# U) Q: F& T) ~' D
if(rst) scl<=0;
7 K% l! P% i& {# @" ]4 T. Welse scl<=~scl;
4 m: z0 r( O) U: [' d( [# y//i2c sda
9 x/ ~' p4 L3 }$ @2 lalways @(posedge clk or posedge rst)
0 r) N1 q) P7 h) E$ j Aif(rst)
: W1 \4 t/ n, N$ U begin
- O( U- u, F e5 d$ j2 N9 T/ ]1 M6 U main_state<=0;4 t4 [; B* @6 a2 r( `- o3 A% h2 K
FF<=0;% {/ p8 o8 I; n9 o& M: I/ H
iic_state<=0;
3 K3 g9 ]8 X! b! R! m* u" @& ^/ i sh8out_buf<=0;# h9 {4 J0 M" O9 G- p
cnt<=0;2 e4 }- L/ ]& d$ \" u% K
rdata<=0;
/ l$ ?& R5 \ l4 k9 ^ check_done<=0;
! H7 ?, w1 c+ o" C time_cnt<=0;
' Y* x8 @7 B4 @' a+ r* f wait_cnt<=0;
+ M0 c; m" J: f- P. x7 j2 V) M end5 W( C9 h4 Q+ P6 ~" y
else: n" K2 z$ J( T4 W3 q- I: `, ^
begin: I$ a8 ?- q/ _- d
case(main_state)
1 _0 G4 G$ i/ _9 B, _0 @$ u: _4 z 0: if(start) main_state<=1;! H/ V! @& F) d5 c
else main_state<=0;
& `2 f0 P) i5 H# t! Y( M% f" o 1: if(FF)9 G2 R6 I7 i' Z$ L; Z& U
begin
+ I. s2 v/ `3 K) t$ l FF<=0;3 h$ @; D1 Q' ?$ I3 ~8 l
main_state<=2;0 s) D4 Y6 H- A. ]% Z
end
- L& Q7 A) z N+ T7 t else
! R" a5 S5 k3 U8 U6 d$ z, t% |" [ begin' a, c8 n, d% v$ L* Q
iic_write(8'h72,8'hC7,8'h00);
m7 |* \4 E! d% m0 X main_state<=1;, `: L- s& l7 s8 V( ^
end
. S- c3 h/ T9 @& f( N# b" N: Z 2: if(wait_cnt==10)% }4 P0 q! _" i" G! K
begin" {' p+ y: ]: Q) |
wait_cnt<=0;
+ Q; O3 x8 {' W8 E, o main_state<=3;
4 Y1 s0 r" Z: d9 N B4 ^6 c end- m* b5 [9 X/ p0 q: j
else wait_cnt<=wait_cnt+1;
! t! X0 @/ O& Z: i1 ` E 3: if(FF)
3 M6 e- R' X( g0 c% P4 i begin
" L/ p( Z9 _% M& j/ O2 O: i FF<=0;- Z! v$ f- ~5 f7 Z
main_state<=4;
3 e/ \4 x" `, }- o% R- \( D end
) Y9 E; j" L, \1 t, o4 s# H else$ b4 V4 w1 e3 ?3 \- E e
begin" {# ~& t3 L- X) D/ }; \; m
iic_write(8'h72,8'h1a,8'h01);
: j0 C$ @% |" \+ x) K6 | main_state<=3;
+ f, _) E- s' X6 ^1 A end
" }, j( V0 o) @4 k; h+ s+ k4 S 4: if(wait_cnt==10)
' {2 i% T/ a4 t B' Z+ G begin4 e' S& k9 d( j$ o" g" c
wait_cnt<=0;, o k0 a6 }& V' S3 B A/ r
main_state<=5;5 P- `5 v \- u" n6 Z2 y
end! ~3 z3 p- f5 z, V' W" K4 W
else wait_cnt<=wait_cnt+1;
' r! z1 n* G' A9 w1 B 5: main_state<=5;$ h6 g7 D& W6 A# l
# F! c, T! u. {) E/ J1 S, ?
default:" V, ?5 _; K, i2 s
begin2 F" m$ d# D5 N& ]3 H6 T
main_state<=0;2 v% ~5 ^$ w* j: |4 \# x6 k, R
FF<=0;7 u; P. U" G) u; Z+ v# M
iic_state<=0;
& }) |+ F8 l) h5 ^, l8 l sh8out_buf<=0;
4 R9 N8 k X. q8 A! J cnt<=0;
$ K8 ?1 L2 K& r& t' B rdata<=0;- M8 o/ x$ e7 V0 h& {; E
end# p& y( E) _1 q! Q
/ y! Q& T- c6 m0 w; z! h0 v( ~
endcase q s7 G' U! ^9 ?- h8 k" x
end& e$ X @! Z6 R* t( ^! Q
8 g, I2 P# R# E H0 N% s4 O B0 b
task iic_write;
+ Q' R' @6 W* Rinput [7:0] slv_addr;; j( n2 b3 }0 W- j; ^ K( d7 ?
input [7:0] addr;
7 z* @: Q9 D8 }input [7:0] wdata;- Y% O; b3 Z i3 b" b
begin
7 l9 q9 i$ N7 K% f$ y8 n case (iic_state)! l8 K: e. ` |* Y* x; L
0:
2 m( c& w t6 m4 i( \6 W3 C if(!scl) //start3 P. R7 f6 v' W
begin6 v4 P" g6 d* |, v& I
link_sda <= 1;
1 q# P1 q5 P$ K0 P' s( ? sda_buf <= 1;0 A: Q6 g2 @ F4 }6 R
iic_state <= 1;5 ~( {1 C# b' ?- ~
end- n9 ?# B( T: Z1 V6 J6 F; g; G f
1:$ g' u' W$ u" b8 d0 r
if(scl)
; j* F& k& c; N/ J begin) p9 K& [2 y( c/ e0 c
sh8out_buf[7:0] <= {slv_addr[7:1],1'b0};
( ]7 M8 F, P' P5 s/ o/ h link_sda <= 1;
+ y; Y- {2 _& r( ?. E/ T8 p5 N4 v sda_buf <= 0;1 k% {9 ?* c' `2 |: C& u) t
iic_state <= 2;
0 `% a/ M& u: }- z" E# d/ K end/ n% P9 r( E* m0 Z, ?
2:
) i" o; \9 ?' R6 a; s& b9 U- Q/ G if(!scl) //device address
) m- o0 _! S4 v2 ~ begin9 z: {% j! T/ z! o6 b' G' P. A
if(cnt==8)' r v+ }$ L0 ~# y* B" c6 W$ B
begin% }: c# C8 T6 Z& Z4 c9 ]+ n0 [ d/ l/ I
link_sda <= 0;/ I5 ?4 O6 r+ A# t
cnt <= 0;/ i, [3 V* z7 I" ?( [
iic_state <= 3;
" Q% F: U- [" L8 f; ?# w% l end0 j/ E% V$ O; B: T0 [
else
% J+ a: l5 [5 m) d( b! } begin, Y6 n" v8 {- j6 u( g8 g3 z
link_sda <= 1;
! B3 M6 W$ I4 A4 f sda_buf <= sh8out_buf[7];
' E1 h( l% z# t2 a* e0 L: F7 | cnt <= cnt+1;, y3 z4 E9 I/ G0 u+ c; X& W9 a
sh8out_buf <= sh8out_buf<<1;: C1 q9 l2 @0 p/ A, B" t
end
% o+ k- r- ], L4 E3 s end
! m" P7 L5 V8 S; {) @& C8 B: N 3:
" a; F- [/ K) T if(scl&&!sda) //ack4 f5 E ]- g4 b6 m% a2 g( ^3 E
begin
/ I& ~6 c+ B' X9 A* R+ F/ w iic_state <= 4;! v' F& I# B6 Y# a& J# b( z, w r
// link_sda <= 1;
P* R7 q A" a g1 k( x sh8out_buf[7:0] <= addr;3 u9 n. h7 h/ \) O {
end
& U: T# f3 G; i! A. o& r7 i 4:9 P2 X9 D' Z$ B
if(!scl) //addr
# w; U- B6 ?# }% ? j* _0 E begin+ ?: O8 L# x% H4 y. g& q" j
if(cnt==8)
3 p. t5 a5 J" ] begin$ y- w) S2 \2 w0 E2 C
link_sda <= 0;( D2 _2 `$ V% p" L
cnt <= 0;! r6 G& @. Z2 }$ w0 J
iic_state <= 5;# D8 Y: f U) _% } z, I
end+ G+ y+ d) T4 B5 Z }
else2 c4 `+ a9 n- A
begin
/ M# c+ t2 u, k1 W4 b link_sda <= 1;' Q! @% k3 }/ r( t7 r
sda_buf <= sh8out_buf[7];" N {% f, c0 A: ~! E
cnt <= cnt+1;
, \; o: U, V$ P6 a sh8out_buf <= sh8out_buf<<1;
3 K6 J- x- A3 E. M& ~ end- o0 y2 N1 g$ t8 j$ p3 `$ F
end
* Y) Z: p8 E: f7 T- V 5:
! l' `3 |% ], Z( l8 U- r4 F if(scl&&!sda) //receive ack
5 k1 V2 Y6 Y5 `5 S begin+ {( U x7 n9 [& E% j
iic_state <= 6;. B: g& `. s7 i' F7 y
//link_sda <= 1;
- v# v9 K+ d3 p" I+ H sh8out_buf <=wdata;
$ e7 M0 z! T' G# m$ i$ N9 {' j end" x, T" |) g' x6 G3 ]. n/ _ g
6:& ? u; h2 v$ z" G8 m" Q& U
if(!scl) //data
2 C% l+ l! A0 U/ F) k begin, m8 L0 g$ b2 `7 {1 H4 @3 e% k' F
if(cnt==8)
7 D0 l8 H7 R& ?0 Y, N/ X begin2 V0 E ~6 X* G8 ~1 }2 X
link_sda <= 0;( I- o* r7 u9 T& w, y& ~/ y
cnt <= 0;
& Q3 W7 ?* W1 k) m( \6 V iic_state <= 7;/ Y( j/ g- r/ ^ }6 D! ?
end
1 b8 }& O7 [- r/ t \0 R2 B else y; Z# I! Y1 f% K" P( u$ W# I6 ]
begin
/ h. _* Z8 {, F+ ] link_sda <= 1;
8 H: y$ L0 i' [3 h) b6 x2 T# F! q sda_buf <= sh8out_buf[7];
* r! ]+ k& l& y cnt <= cnt+1;7 a1 s+ _8 G6 h0 ^* ]4 m |
sh8out_buf <= sh8out_buf<<1;; ?, d2 U5 E0 @# A( u
end
- e2 B* g* R; J% J% v end. Y' v; V6 q a' n! \' W, \, u
7:
( Z/ I1 O- n, X: S O+ h if(scl&&!sda) //receive ack9 ]/ V, n4 V/ D! P. M; k
begin# H {4 p) i4 H" ^% W) _
iic_state <= 8;& G3 a- ?# I. s0 _
// link_sda <= 1;
b0 m( J4 N8 F. S end
8 o, N! P) _6 V 8:
, w$ g0 G. f( {, B6 B9 o3 D if(!scl) //stop
& [2 @) M2 b7 K0 A, ^ begin/ e; t8 d2 v3 t
sda_buf <= 0;
& r6 i0 l! p2 U9 v link_sda <= 1;
" ]+ I- e4 |& g! I4 S6 s* u iic_state <= 9;- I' s: g- Q# M1 Y9 z' ~/ y
end
- |; F' \5 ] L2 e 9:* }, }. X( |% @; s' ~' E4 {* ?
if(scl)
$ G& f) s) P z: n R9 M8 v begin
6 b/ D7 o& y' ?/ h! u, n sda_buf <= 1;
. N$ M* s; D; N- L iic_state <= 10;
! T' d9 x! C. l- p6 p( Z end0 w. p. Z% {" l# d
10:* v; q4 N+ s8 ^* @+ A6 s# ^% X& v
begin
2 n9 p! n% I0 l+ m G' L FF <= 1;; r% [3 M$ L% f2 k7 ^9 ~% @- c; ]7 Q, |
sh8out_buf <= 0;
) ~: |, r6 g1 f- h" k- W2 [3 c link_sda <= 0;: z8 | C+ h% K# R/ w
iic_state <= 0;
2 P1 z; m7 Z# {+ l/ m8 e end
/ z* l6 o" G: M/ Q+ A endcase
! |$ U% C+ v1 A- ^: ]. H: \end # g" G: S9 c, G" q7 Y- \
endtask5 d' R& r: C0 d+ v! |% {1 K
3 d8 ~5 n/ C! j- ?: X# g o% Ytask iic_read;
( @ t! l" ~/ B, ^8 d6 G; Jinput [7:0] slv_addr;/ T' A- v. e- ]1 f' _0 f
input [7:0] addr;+ C0 M6 ?* c k" w6 i* d7 m8 E( P
output [7:0] odata;6 Y2 [6 H! u6 S8 Q' z$ y
begin
/ }) T6 c/ I# M case (iic_state)
c0 }* K( P# b9 f" ~! b 0:+ b$ K a2 \5 p6 v3 x
if(!scl) //start
5 C- o3 C- Q$ {8 C: l$ \+ S begin$ _0 K/ @ I" o2 q0 ]) L- ~
link_sda <= 1;
' ^! ] e* s5 R [( U sda_buf <= 1;
4 q3 H: }+ R4 Y, ^% z iic_state <= 1;/ ?+ i# R* }7 @2 F; w9 v
end
% U" _- K) a' D9 X; G8 { 1:
9 M& z5 O: D* } if(scl); K$ z6 d! h& ?3 H# H# c% D
begin# o7 a. S, C. i
sh8out_buf[7:0] <= {slv_addr[7:1],1'b0};; D2 G+ j! |- o5 v; N% G& N
link_sda <= 1;
9 s9 M& x1 I8 q) [# W+ ^6 {8 X4 m sda_buf <= 0;; e0 H1 |% ~& q
iic_state <= 2;
8 E( @( [' ^6 E! R1 H end
' Q) n A- Q- E4 ^' J 2:
! [) E9 u- Q1 X) ?, ]9 n- } if(!scl) //device address) s( N9 l9 w$ k1 q; R, f
begin
$ E6 ~" g6 V9 u% n9 B$ l- D if(cnt==8)1 H3 M3 c6 B0 D
begin
- ]* T" }8 c# g8 h$ i7 Q link_sda <= 0;) E' A1 H( `$ s, ?5 P" z, J
cnt <= 0;
3 J3 V0 G2 G- }& |/ H iic_state <= 3;3 }" l) r1 Y- {1 t# b5 p
end
( ?- p/ C4 M, n. z4 x else
* l; P6 K6 Z9 f; q begin
+ \2 ]% a4 m$ H8 b" i/ C& Q. ` link_sda <= 1;5 [; m& B% _0 i
sda_buf <= sh8out_buf[7];" K) F! E# o% y) g7 v Q3 Z
cnt <= cnt+1;: S/ t; y- M. J% [; f6 m4 p
sh8out_buf <= sh8out_buf<<1;
* X* h1 ^0 I. }% e k( f/ K; I end: y$ T1 H! L0 e, n- w- ]
end
0 ?5 F' ?# w# V. I: u2 w 3:1 R' |+ K. J& n) N
if(scl&&!sda) //ack
+ F! v, ~- ~ S$ ~8 P) K begin
/ C" z: t- o4 m iic_state <= 4;, a. n R; Q9 n+ h6 r3 T; I- R" M) o
//link_sda <= 1;
# b1 I/ ]3 `0 T% F' T sh8out_buf[7:0] <= addr;
: j# A: \ G: `+ C3 i end2 }- w" p; C# k% u5 c, D
4:
/ f& a' k$ `# [7 ^, s if(!scl) //write addr
) T1 v' I8 f- U4 u, S9 p begin
& S( ]! @, m6 i3 O if(cnt==8)+ [/ a' v4 G' Q, f
begin
, ?( i3 `- K; x+ A" C2 Q3 ]. j. k link_sda <= 0;% O# D% P! {5 ?9 P8 V# ]9 |. g
cnt <= 0;
7 o* u. E6 k# H' _: f iic_state <= 5;
. s7 f( R2 N" ^( Z3 B9 ^# } end
3 K) K1 z$ N, Z) s, r; G/ N$ ? else; P- M1 ^) }( S% [
begin, s8 s. m+ `& k% @1 ?
link_sda <= 1;
( P/ Y* ~5 F* W" V+ n& j6 b) {/ K3 a I2 A sda_buf <= sh8out_buf[7];9 f- c: E- s: m" u* j. N
cnt <= cnt+1;- J' V# ` A6 \3 g5 h3 U6 u
sh8out_buf <= sh8out_buf<<1;
# K7 _8 R/ {# }4 m0 [% M end5 z- R0 \6 U& [3 a1 }; I6 x
end
, M9 V7 o0 ]6 N6 v# q+ Q 5:
6 M* e2 M; k) V; W+ ? if(scl&&!sda) //receive ack5 N, A$ f* w1 \
begin
+ |8 y- _- O- b1 F& ~ iic_state <= 6;; N" n+ ]- B4 e) t! _# u2 L- L
end
u# `7 @6 m# `# q( F 6:) X* z/ |7 w8 s! q6 C# @: _
if(!scl) //restart# ~5 [0 ~) V' e) j# L; @4 n
begin; b7 ^2 H6 p# q: O* \( w% n! e8 v
link_sda <= 1;; [ ~( g& ~$ Q( ]' @
sda_buf <= 1;# }. h Q. \# R( X) q$ ?0 Y
iic_state <= 7;
$ e1 f: a- s. z end
' B/ B+ F" u1 n; G8 s! {- z4 Q# G& J 7:
/ k5 j3 D2 x5 @$ y7 t/ @ if(scl)% u; M8 ?0 S' m" R
begin
& F8 ]/ @; \ X5 Y sh8out_buf[7:0] <= {slv_addr[7:1],1'b1};" Q7 W& _6 `$ d+ m
link_sda <= 1; + ^* T! p6 S5 n; Q8 y% B2 B
sda_buf <= 0;
; ?+ q# T# Q% k, O3 D+ w6 w, {9 { iic_state <= 8;
4 }- {; ]9 y. ` end/ Q) E6 o: _5 M! S( D5 X. _8 o+ a
8:if(!scl) //device address
' s' u7 S. a f begin. [/ D6 t0 m4 J( f( X
if(cnt==8)
$ U) `* ^( b9 @$ d; h1 }; H% T begin
2 e) i$ e ]& K( g link_sda <= 0;4 Z- y8 o0 X" f7 [3 B+ K' V
cnt <= 0;6 r1 K, w6 _; R4 c- C [
iic_state <= 9;
' V* Q8 l. b( V8 U1 b( C end
: n$ q# Y; J# j# K# g else
0 p, W. r# m0 f. r: T/ l0 I- N begin! u9 \! D7 j8 J- M6 t. f
link_sda <= 1;; v2 t. I$ W" e/ R$ y0 M
sda_buf <= sh8out_buf[7];' X# D: i6 B1 G7 C* \! {! L
cnt <= cnt+1;
- o# _* @" X+ q1 ^ sh8out_buf <= sh8out_buf<<1;: \2 g' ^/ F" m$ \/ ~/ H
end: [7 b( U. D+ ?. j/ C
end* {5 ]* V/ `, V/ Q
9:
8 s8 x7 \1 d# V& u if(scl&&!sda) //receive ack5 s5 y& {$ z6 x$ ~3 U
begin
M1 |% o5 ?6 v6 ]7 B iic_state <= 10;
" k1 ?% G$ G: r. V, o* l G end
! v3 A9 c4 n W z 10:
0 E+ n3 p3 o: {: ]/ t6 B+ n7 o: L1 ~ if(scl) //read data
; x7 P! F- |( \2 J begin
I* W3 N" e, H4 N y: d if(cnt==7)$ t7 Y! |4 ]7 s& x
begin
- o) T7 Y+ [. k8 h. J: u( A cnt <= 0;7 N' v O7 e- R4 m
//odata[0] <=sda;
- U; v& E& I N: Y. m6 R Q iic_state <= 11;0 K$ E9 ^0 K* B
end4 M' C4 @) E5 \( R
else
1 q2 ]8 ]8 L/ P% y4 [ begin
. @1 c" M+ |8 \' x& p6 d odata[7-cnt]<=sda;( K; V( H3 }; _( K# M) C2 h
cnt<=cnt+1;4 T6 F( j$ o% M
end
5 d9 u6 h$ _, o2 \6 C end7 _$ a+ B% c5 F2 V9 A: |
11:
! ^% l' q9 n& ]. I! l2 s if(!scl) //send ack. Z# i8 ^3 j+ D: C6 z* o/ U
begin) f5 ?# g8 Q F |
sda_buf <= 1;# W3 z* G9 z# k* h' H
link_sda <= 1;# `/ ?0 y9 i% A" B, N$ A
/ K+ _7 l, i" K V. H3 ?- P! m end }; P3 W) J: Q+ ~! [
else
& z* r0 p0 ~! ~ begin
2 W M- X5 X+ s6 w iic_state <= 12;
8 @' G. h# Q! r0 q) ^ end
8 C9 q/ J- A' z% [, F9 l 12:
7 B2 Y) A( ` q4 k& J' F if(!scl) //stop
+ O3 `( A0 ?/ Y% P; t" ]5 [6 A, O begin4 M0 h- L" e2 M: f. ?
sda_buf<=0;
3 N3 C; l/ R5 D7 e link_sda <= 1;; b- t! G/ q- p; o
iic_state <= 13;
' c) F2 F$ A, U- L! B0 c: z end' I7 n% m4 M" x; K
13:
# T$ U/ a5 N5 W& z if(scl)
7 r: g( K% P" q. n& m! p begin7 ?, g8 h1 J" R# p
sda_buf<=1;+ T! N" l" q# V
iic_state <= 14;
9 }& S" e6 y$ W4 _9 n1 Z1 @3 h end* L/ V4 K- I/ q2 {& {
14:
3 u8 J' Z+ g, m; m/ l begin( y# o3 W, R: g& T2 ?9 W
FF<=1;
- Z' t% M: q: V& a1 i6 a sh8out_buf <= 0;
9 p6 x. v6 k, e link_sda <= 0;3 u! o: d& K+ E1 t1 e5 n; w# K: k, \
iic_state <= 0;, `! l* Z9 j0 I3 ~( i
end
. W% Q/ s N/ w- R+ J; N endcase
% u; H- v2 u: [& o# Fend
! f: f0 B* c0 Q- Bendtask* d7 E" [/ q' b, U
3 ?/ g& T% C: |* m* v- e1 Jendmodule
# a- W" g; A' [, s: O) F7 g. n0 b0 y | . R* _8 I( x, Z6 h
$ C' A5 q* p1 A! O. _
0 V9 }. ~, y. I0 g, L1 ~& Z, ]0 R0 e5 |4 W7 Z
8 k9 ]$ x" @$ W+ G+ S! H | 2 q: H# W. @3 i' `# }( p
| : u% a, B2 E, n; {
|
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