1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
module fifo36_to_ll8
(input clk, reset,
input [35:0] f36_data,
input f36_src_rdy_i,
output f36_dst_rdy_o,
output reg [7:0] ll_data,
output ll_sof_n,
output ll_eof_n,
output ll_src_rdy_n,
input ll_dst_rdy_n,
output [31:0] debug);
wire ll_sof, ll_eof, ll_src_rdy;
assign ll_sof_n = ~ll_sof;
assign ll_eof_n = ~ll_eof;
assign ll_src_rdy_n = ~ll_src_rdy;
wire ll_dst_rdy = ~ll_dst_rdy_n;
wire f36_sof = f36_data[32];
wire f36_eof = f36_data[33];
wire f36_occ = f36_data[35:34];
wire advance, end_early;
reg [1:0] state;
assign debug = {29'b0,state};
always @(posedge clk)
if(reset)
state <= 0;
else
if(advance)
if(ll_eof)
state <= 0;
else
state <= state + 1;
always @*
case(state)
0 : ll_data = f36_data[31:24];
1 : ll_data = f36_data[23:16];
2 : ll_data = f36_data[15:8];
3 : ll_data = f36_data[7:0];
default : ll_data = f36_data[31:24];
endcase // case (state)
assign ll_sof = (state==0) & f36_sof;
assign ll_eof = f36_eof & (((state==0)&(f36_occ==1)) |
((state==1)&(f36_occ==2)) |
((state==2)&(f36_occ==3)) |
(state==3));
assign ll_src_rdy = f36_src_rdy_i;
assign advance = ll_src_rdy & ll_dst_rdy;
assign f36_dst_rdy_o = advance & ((state==3)|ll_eof);
assign debug = state;
endmodule // ll8_to_fifo36
|
