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module fifo36_to_ll8
(input clk, input reset, input clear,
input [35:0] f36_data,
input f36_src_rdy_i,
output f36_dst_rdy_o,
output [7:0] ll_data,
output ll_sof,
output ll_eof,
output ll_src_rdy,
input ll_dst_rdy,
output [31:0] debug);
// Shortfifo on input to guarantee no deadlock
wire [35:0] f36_data_int;
wire f36_src_rdy_int, f36_dst_rdy_int;
reg [7:0] ll_data_int;
wire ll_sof_int, ll_eof_int, ll_src_rdy_int, ll_dst_rdy_int;
fifo_short #(.WIDTH(36)) head_fifo
(.clk(clk),.reset(reset),.clear(clear),
.datain(f36_data), .src_rdy_i(f36_src_rdy_i), .dst_rdy_o(f36_dst_rdy_o),
.dataout(f36_data_int), .src_rdy_o(f36_src_rdy_int), .dst_rdy_i(f36_dst_rdy_int),
.space(),.occupied() );
// Actual fifo36 to ll8, can deadlock if not connected to shortfifo
wire f36_sof_int = f36_data_int[32];
wire f36_eof_int = f36_data_int[33];
wire f36_occ_int = f36_data_int[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_int)
state <= 0;
else
state <= state + 1;
always @*
case(state)
0 : ll_data_int = f36_data_int[31:24];
1 : ll_data_int = f36_data_int[23:16];
2 : ll_data_int = f36_data_int[15:8];
3 : ll_data_int = f36_data_int[7:0];
default : ll_data_int = f36_data_int[31:24];
endcase // case (state)
assign ll_sof_int = (state==0) & f36_sof_int;
assign ll_eof_int = f36_eof_int & (((state==0)&(f36_occ_int==1)) |
((state==1)&(f36_occ_int==2)) |
((state==2)&(f36_occ_int==3)) |
(state==3));
assign ll_src_rdy_int = f36_src_rdy_int;
assign advance = ll_src_rdy_int & ll_dst_rdy_int;
assign f36_dst_rdy_int= advance & ((state==3)|ll_eof_int);
// Short FIFO on output to guarantee no deadlock
ll8_shortfifo tail_fifo
(.clk(clk), .reset(reset), .clear(clear),
.datain(ll_data_int), .sof_i(ll_sof_int), .eof_i(ll_eof_int),
.error_i(0), .src_rdy_i(ll_src_rdy_int), .dst_rdy_o(ll_dst_rdy_int),
.dataout(ll_data), .sof_o(ll_sof), .eof_o(ll_eof),
.error_o(), .src_rdy_o(ll_src_rdy), .dst_rdy_i(ll_dst_rdy));
endmodule // fifo36_to_ll8
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