u1p: do padding outside of gpif_rd, in packet_splitter

5 files changed, 188 insertions, 14 deletions

diff --git a/usrp2/gpif/Makefile.srcs b/usrp2/gpif/Makefile.srcs
index d7eaf9fca..bf2b7f74d 100644
--- a/usrp2/gpif/Makefile.srcs
+++ b/usrp2/gpif/Makefile.srcs
@@ -10,4 +10,5 @@ gpif.v \
 gpif_wr.v \
 gpif_rd.v \
 packet_reframer.v \
+packet_splitter.v \
 ))
diff --git a/usrp2/gpif/gpif.v b/usrp2/gpif/gpif.v
index 052a66bff..2a9fd901e 100644
--- a/usrp2/gpif/gpif.v
+++ b/usrp2/gpif/gpif.v
@@ -85,8 +85,8 @@ module gpif
 
    wire [35:0] 	  rx36_data, rx_data;
    wire 	  rx36_src_rdy, rx36_dst_rdy, rx_src_rdy, rx_dst_rdy;
-   wire [18:0] 	  rx19_data;
-   wire 	  rx19_src_rdy, rx19_dst_rdy;
+   wire [18:0] 	  rx19_data, splt_data;
+   wire 	  rx19_src_rdy, rx19_dst_rdy, splt_src_rdy, splt_dst_rdy;
    wire [18:0] 	  resp_data, resp_int1, resp_int2;
    wire 	  resp_src_rdy, resp_dst_rdy;
    wire 	  resp_src_rdy_int1, resp_dst_rdy_int1, resp_src_rdy_int2, resp_dst_rdy_int2;
@@ -96,18 +96,23 @@ module gpif
       .datain(rx_data), .src_rdy_i(rx_src_rdy), .dst_rdy_o(rx_dst_rdy),
       .dataout(rx36_data), .src_rdy_o(rx36_src_rdy), .dst_rdy_i(rx36_dst_rdy));
 
-   fifo36_to_fifo19 #(.LE(1)) f36_to_f19   // FIXME Endianness?
+   fifo36_to_fifo19 #(.LE(1)) f36_to_f19
      (.clk(fifo_clk), .reset(fifo_rst), .clear(clear_rx),
       .f36_datain(rx36_data), .f36_src_rdy_i(rx36_src_rdy), .f36_dst_rdy_o(rx36_dst_rdy),
       .f19_dataout(rx19_data), .f19_src_rdy_o(rx19_src_rdy), .f19_dst_rdy_i(rx19_dst_rdy) );
 
+   packet_splitter #(.FRAME_LEN(256)) packet_splitter
+     (.clk(fifo_clk), .reset(fifo_rst), .clear(clear_rx),
+      .data_i(rx19_data), .src_rdy_i(rx19_src_rdy), .dst_rdy_o(rx19_dst_rdy),
+      .data_o(splt_data), .src_rdy_o(splt_src_rdy), .dst_rdy_i(splt_dst_rdy));
+     
    gpif_rd gpif_rd
      (.gpif_clk(gpif_clk), .gpif_rst(gpif_rst),
       .gpif_data(gpif_d_out), .gpif_rd(RD), .gpif_ep(EP),
       .gpif_empty_d(DE), .gpif_empty_c(CE),
       
       .sys_clk(fifo_clk), .sys_rst(fifo_rst),
-      .data_i(rx19_data), .src_rdy_i(rx19_src_rdy), .dst_rdy_o(rx19_dst_rdy),
+      .data_i(splt_data), .src_rdy_i(splt_src_rdy), .dst_rdy_o(splt_dst_rdy),
       .resp_i(resp_data), .resp_src_rdy_i(resp_src_rdy), .resp_dst_rdy_o(resp_dst_rdy),
       .debug(debug_rd) );
 
diff --git a/usrp2/gpif/gpif_rd.v b/usrp2/gpif/gpif_rd.v
index e79b275b3..ed0721a36 100644
--- a/usrp2/gpif/gpif_rd.v
+++ b/usrp2/gpif/gpif_rd.v
@@ -32,8 +32,7 @@ module gpif_rd
       .arst(sys_rst));
 
    reg [7:0] 	packet_count;
-   reg 		do_padding;
-   wire 	consume_data_line = gpif_rd & ~gpif_ep & ~read_count[8] & ~do_padding;
+   wire 	consume_data_line = gpif_rd & ~gpif_ep & ~read_count[8];
    wire 	produce_eop = src_rdy_int & dst_rdy_int & data_int[17];
    wire 	consume_sop = consume_data_line & final_rdy_data & data_o[16];
    wire 	consume_eop = consume_data_line & final_rdy_data & data_o[17];
@@ -54,14 +53,6 @@ module gpif_rd
 
    always @(negedge gpif_clk)
      if(gpif_rst)
-       do_padding <= 0;
-     else if(~gpif_rd)
-       do_padding <= 0;
-     else if(consume_eop)
-       do_padding <= 1;   
-       
-   always @(negedge gpif_clk)
-     if(gpif_rst)
        gpif_empty_d <= 1;
      else
        gpif_empty_d <= ~|packet_count;
diff --git a/usrp2/gpif/gpif_tb.v b/usrp2/gpif/gpif_tb.v
new file mode 100644
index 000000000..1cb84e9fb
--- /dev/null
+++ b/usrp2/gpif/gpif_tb.v
@@ -0,0 +1,98 @@
+
+module gpif_tb();
+   
+   reg sys_clk = 0;
+   reg sys_rst = 1;
+   reg gpif_clk = 0;
+   reg gpif_rst = 1;
+      
+   reg [15:0] gpif_data;
+   reg 	      WR = 0, EP = 0;
+
+   wire       CF, DF;
+   
+   wire       gpif_full_d, gpif_full_c;
+   wire [18:0] data_o, ctrl_o;
+   wire        src_rdy, dst_rdy;
+   wire        ctrl_src_rdy, ctrl_dst_rdy;
+
+   assign ctrl_dst_rdy = 1;
+   assign dst_rdy = 1;
+   
+   initial $dumpfile("gpif_tb.vcd");
+   initial $dumpvars(0,gpif_tb);
+
+   initial #1000 gpif_rst = 0;
+   initial #1000 sys_rst = 0;
+   always #64 gpif_clk <= ~gpif_clk;
+   always #47.9 sys_clk <= ~sys_clk;
+
+   wire [18:0] data_int;
+   wire        src_rdy_int, dst_rdy_int;
+   
+   gpif_wr gpif_write
+     (.gpif_clk(gpif_clk), .gpif_rst(gpif_rst), 
+      .gpif_data(gpif_data), .gpif_wr(WR), .gpif_ep(EP),
+      .gpif_full_d(DF), .gpif_full_c(CF),
+      
+      .sys_clk(sys_clk), .sys_rst(sys_rst),
+      .data_o(data_int), .src_rdy_o(src_rdy_int), .dst_rdy_i(dst_rdy_int),
+      .ctrl_o(ctrl_o), .ctrl_src_rdy_o(ctrl_src_rdy), .ctrl_dst_rdy_i(ctrl_dst_rdy) );
+
+   packet_reframer tx_packet_reframer 
+     (.clk(sys_clk), .reset(sys_rst), .clear(0),
+      .data_i(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int),
+      .data_o(data_o), .src_rdy_o(src_rdy), .dst_rdy_i(dst_rdy));
+
+   packet_splitter #(.FRAME_LEN(256)) rx_packet_splitter
+     (.clk(sys_clk), .reset(sys_rst), .clear(0),
+      .data_i(data_o), .src_rdy_i(src_rdy), .dst_rdy_o(dst_rdy),
+      .data_o(data_o), .src_rdy_o(src_rdy), .dst_rdy_i(dst_rdy));
+
+   always @(posedge sys_clk)
+     if(ctrl_src_rdy & ctrl_dst_rdy)
+       $display("CTRL: %x",ctrl_o);
+
+   always @(posedge sys_clk)
+     if(src_rdy & dst_rdy)
+       begin
+	  if(data_o[16])
+	    $display("<-------- DATA SOF--------->");
+	  $display("DATA: %x",data_o);
+	  if(data_o[17])
+	    $display("<-------- DATA EOF--------->");
+       end
+   
+   initial
+     begin
+	#10000;
+	repeat (1)
+	  begin
+	     WR <= 1;
+	     gpif_data <= 10;  // Length
+	     @(posedge gpif_clk);
+	     gpif_data <= 16'h00;
+	     @(posedge gpif_clk);
+	     repeat(254)
+	       begin
+		  gpif_data <= gpif_data + 1;
+		  @(posedge gpif_clk);
+	       end
+	     WR <= 0;
+	     repeat (20)
+	       @(posedge gpif_clk);
+	     WR <= 1;
+	     gpif_data <= 16'h5;
+	     @(posedge gpif_clk);
+	     repeat(254)
+	       begin
+		  gpif_data <= gpif_data - 1;
+		  @(posedge gpif_clk);
+	       end
+	  end
+     end // initial begin
+   
+   initial #100000 $finish;
+   
+     
+endmodule // gpif_tb
diff --git a/usrp2/gpif/packet_splitter.v b/usrp2/gpif/packet_splitter.v
new file mode 100644
index 000000000..43515dd8b
--- /dev/null
+++ b/usrp2/gpif/packet_splitter.v
@@ -0,0 +1,79 @@
+
+// Split vita packets longer than one GPIF frame, add padding on short frames
+
+module packet_splitter
+  #(parameter FRAME_LEN=256)
+   (input clk, input reset, input clear,
+    input [18:0] data_i,
+    input src_rdy_i,
+    output dst_rdy_o,
+    output [18:0] data_o,
+    output src_rdy_o,
+    input dst_rdy_i);
+   
+   reg [1:0] state;
+   reg [15:0] length;
+   reg [15:0] frame_len;
+   
+   localparam PS_IDLE = 0;
+   localparam PS_FRAME = 1;
+   localparam PS_NEW_FRAME = 2;
+   localparam PS_PAD = 3;
+   
+   always @(posedge clk)
+     if(reset | clear)
+       state <= PS_IDLE;
+     else
+       case(state)
+	 PS_IDLE :
+	   if(src_rdy_i & dst_rdy_i)
+	     begin
+		length <= { data_i[14:0],1'b0};
+		frame_len <= FRAME_LEN;
+		state <= PS_FRAME;
+	     end
+	 PS_FRAME :
+	   if(src_rdy_i & dst_rdy_i)
+	     if(frame_len == 0)
+	       if(length == 0)
+		 state <= PS_IDLE;
+	       else
+		 begin
+		    state <= PS_NEW_FRAME;
+		    frame_len <= FRAME_LEN;
+		    length <= length - 1;
+		 end
+	     else
+	       if(length == 0)
+		 begin
+		    frame_len <= frame_len - 1;
+		    state <= PS_PAD;
+		 end
+	 PS_NEW_FRAME :
+	   if(src_rdy_i & dst_rdy_i)
+	     begin
+		frame_len <= frame_len - 1;
+		state <= PS_FRAME;
+	     end
+	 PS_PAD :
+	   if(dst_rdy_i)
+	     if(frame_len == 0)
+	       state <= PS_IDLE;
+	     else
+	       frame_len <= frame_len - 1;
+
+       endcase // case (state)
+   
+	
+   
+   assign dst_rdy_o = dst_rdy_i & (state != PS_PAD);
+   assign src_rdy_o = src_rdy_i | (state == PS_PAD);
+   
+   wire occ_out = 0;
+   wire eof_out = (frame_len == 0) & (state != PS_IDLE);
+   wire sof_out = (state == PS_IDLE) | (state == PS_NEW_FRAME);
+
+   wire [15:0] data_out = data_i[15:0];
+   assign data_o = {occ_out, eof_out, sof_out, data_out};
+   
+endmodule // packet_splitter