From c32f4fbc8973633280249399d5d5a937ef0f1f3e Mon Sep 17 00:00:00 2001 From: Matt Ettus Date: Thu, 21 Oct 2010 13:08:23 -0700 Subject: should combine the randomizer with flow_control --- usrp2/extramfifo/ext_fifo.v | 125 ++++++++++++++++++++++++++++++-------------- 1 file changed, 87 insertions(+), 38 deletions(-) (limited to 'usrp2/extramfifo/ext_fifo.v') diff --git a/usrp2/extramfifo/ext_fifo.v b/usrp2/extramfifo/ext_fifo.v index 2af59a75d..6888617a7 100644 --- a/usrp2/extramfifo/ext_fifo.v +++ b/usrp2/extramfifo/ext_fifo.v @@ -18,7 +18,7 @@ //`define NO_EXT_FIFO module ext_fifo - #(parameter INT_WIDTH=36,EXT_WIDTH=18,RAM_DEPTH=19,FIFO_DEPTH=19) + #(parameter INT_WIDTH=36,EXT_WIDTH=18,RAM_DEPTH=19,FIFO_DEPTH=19) ( input int_clk, input ext_clk, @@ -44,34 +44,29 @@ module ext_fifo wire [EXT_WIDTH-1:0] write_data; wire [EXT_WIDTH-1:0] read_data; - wire full1, empty1; - wire almost_full2, full2, empty2; + wire full1, empty1; + wire almost_full2, full2, empty2; wire [INT_WIDTH-1:0] data_to_fifo; wire [INT_WIDTH-1:0] data_from_fifo; wire [FIFO_DEPTH-1:0] capacity; - + wire space_avail; + wire data_avail; + + // These next 2 lines here purely because ICARUS is crap at handling generate statements. + // Empirically this has been determined to make simulations work. + wire read_input_fifo = space_avail & ~empty1; + wire write_output_fifo = data_avail; - // FIFO buffers data from UDP engine into external FIFO clock domain. - fifo_xlnx_512x36_2clk_36to18 fifo_xlnx_512x36_2clk_36to18_i1 ( - .rst(rst), - .wr_clk(int_clk), - .rd_clk(ext_clk), - .din(datain), // Bus [35 : 0] - .wr_en(src_rdy_i), - .rd_en(space_avail&~empty1), - .dout(write_data), // Bus [17 : 0] - .full(full1), - .empty(empty1)); - - assign dst_rdy_o = ~full1; + assign src_rdy_o = ~empty2; + assign dst_rdy_o = ~full1; `ifdef NO_EXT_FIFO - assign space_avail = ~full2; - assign data_avail = ~empty1; - assign read_data = write_data; + assign space_avail = ~full2; + assign data_avail = ~empty1; + assign read_data = write_data; `else - // External FIFO running at ext clock rate and 18 bit width. + // External FIFO running at ext clock rate and 18 or 36 bit width. nobl_fifo #(.WIDTH(EXT_WIDTH),.RAM_DEPTH(RAM_DEPTH),.FIFO_DEPTH(FIFO_DEPTH)) nobl_fifo_i1 ( @@ -90,27 +85,80 @@ module ext_fifo .write_strobe(~empty1 ), .space_avail(space_avail), .read_data(read_data), - .read_strobe(~almost_full2), + .read_strobe(~almost_full2_spread), .data_avail(data_avail), .capacity(capacity) ); `endif // !`ifdef NO_EXT_FIFO + + + generate + if (EXT_WIDTH == 18 && INT_WIDTH == 36) begin: fifo_g1 + // FIFO buffers data from UDP engine into external FIFO clock domain. + fifo_xlnx_512x36_2clk_36to18 fifo_xlnx_512x36_2clk_36to18_i1 ( + .rst(rst), + .wr_clk(int_clk), + .rd_clk(ext_clk), + .din(datain), // Bus [35 : 0] + .wr_en(src_rdy_i), + .rd_en(read_input_fifo), + .dout(write_data), // Bus [17 : 0] + .full(full1), + .empty(empty1)); + + + // FIFO buffers data read from external FIFO into DSP clk domain and to TX DSP. + fifo_xlnx_512x36_2clk_18to36 fifo_xlnx_512x36_2clk_18to36_i1 ( + .rst(rst), + .wr_clk(ext_clk), + .rd_clk(int_clk), + .din(read_data), // Bus [17 : 0] + .wr_en(write_output_fifo), + .rd_en(dst_rdy_i), + .dout(dataout), // Bus [35 : 0] + .full(full2), + .prog_full(almost_full2), + .empty(empty2)); + end // block: fifo_g1 + else if (EXT_WIDTH == 36 && INT_WIDTH == 36) begin: fifo_g1 + // FIFO buffers data from UDP engine into external FIFO clock domain. + fifo_xlnx_32x36_2clk fifo_xlnx_32x36_2clk_i1 ( + .rst(rst), + .wr_clk(int_clk), + .rd_clk(ext_clk), + .din(datain), // Bus [35 : 0] + .wr_en(src_rdy_i), + .rd_en(read_input_fifo), + .dout(write_data), // Bus [35 : 0] + .full(full1), + .empty(empty1)); + + // FIFO buffers data read from external FIFO into DSP clk domain and to TX DSP. + fifo_xlnx_32x36_2clk fifo_xlnx_32x36_2clk_i2 ( + .rst(rst), + .wr_clk(ext_clk), + .rd_clk(int_clk), + .din(read_data), // Bus [35 : 0] + .wr_en(write_output_fifo), + .rd_en(dst_rdy_i), + .dout(dataout), // Bus [35 : 0] + .full(full2), + .empty(empty2), + .prog_full(almost_full2)); + + end + endgenerate - - // FIFO buffers data read from external FIFO into DSP clk domain and to TX DSP. - fifo_xlnx_512x36_2clk_18to36 fifo_xlnx_512x36_2clk_18to36_i1 ( - .rst(rst), - .wr_clk(ext_clk), - .rd_clk(int_clk), - .din(read_data), // Bus [17 : 0] - .wr_en(data_avail), - .rd_en(dst_rdy_i), - .dout(dataout), // Bus [35 : 0] - .full(full2), - .prog_full(almost_full2), - .empty(empty2)); - assign src_rdy_o = ~empty2; + refill_randomizer #(.BITS(7)) + refill_randomizer_i1 ( + .clk(ext_clk), + .rst(rst), + .full_in(almost_full2), + .full_out(almost_full2_spread) + ); + + always @ (posedge int_clk) debug[31:28] <= {empty2,full1,dst_rdy_i,src_rdy_i }; @@ -118,6 +166,7 @@ module ext_fifo debug[27:0] <= {RAM_WEn,RAM_CE1n,RAM_A[3:0],read_data[17:0],empty1,space_avail,data_avail,almost_full2 }; always@ (posedge ext_clk) -// debug2[31:0] <= {write_data[15:0],read_data[15:0]}; - debug2[31:0] <= 0; + // debug2[31:0] <= {write_data[15:0],read_data[15:0]}; + debug2[31:0] <= 0; + endmodule // ext_fifo -- cgit v1.2.3