module ll8_to_fifo36 (input clk, input reset, input clear, input [7:0] ll_data, input ll_sof_n, input ll_eof_n, input ll_src_rdy_n, output ll_dst_rdy_n, output [35:0] f36_data, output f36_src_rdy_o, input f36_dst_rdy_i ); wire f36_write = f36_src_rdy_o & f36_dst_rdy_i; // Why anybody would use active low in an FPGA is beyond me... wire ll_sof = ~ll_sof_n; wire ll_eof = ~ll_eof_n; wire ll_src_rdy = ~ll_src_rdy_n; wire ll_dst_rdy; assign ll_dst_rdy_n = ~ll_dst_rdy; reg f36_sof, f36_eof; reg [1:0] f36_occ; reg [2:0] state; reg [7:0] dat0, dat1, dat2, dat3; always @(posedge clk) if(ll_src_rdy & ((state==0)|f36_write)) f36_sof <= ll_sof; always @(posedge clk) if(ll_src_rdy & ((state !=4)|f36_write)) f36_eof <= ll_eof; always @(posedge clk) if(ll_eof) f36_occ <= state[1:0] + 1; else f36_occ <= 0; always @(posedge clk) if(reset) state <= 0; else if(ll_src_rdy) case(state) 0 : if(ll_eof) state <= 4; else state <= 1; 1 : if(ll_eof) state <= 4; else state <= 2; 2 : if(ll_eof) state <= 4; else state <= 3; 3 : state <= 4; 4 : if(f36_dst_rdy_i) if(ll_eof) state <= 4; else state <= 1; endcase // case(state) else if(f36_write) state <= 0; always @(posedge clk) if(ll_src_rdy & (state==3)) dat3 <= ll_data; always @(posedge clk) if(ll_src_rdy & (state==2)) dat2 <= ll_data; always @(posedge clk) if(ll_src_rdy & (state==1)) dat1 <= ll_data; always @(posedge clk) if(ll_src_rdy & ((state==0) | f36_write)) dat0 <= ll_data; assign ll_dst_rdy = f36_dst_rdy_i | (state != 4); assign f36_data = {f36_occ,f36_eof,f36_sof,dat0,dat1,dat2,dat3}; // FIXME endianess assign f36_src_rdy_o = (state == 4); endmodule // ll8_to_fifo36