Merge commit '38d5389f3054164a2f04d6e4e8fe381aa5ee03fc' into vrt

9 files changed, 236 insertions, 380 deletions

diff --git a/usrp2/fpga/control_lib/newfifo/.gitignore b/usrp2/fpga/control_lib/newfifo/.gitignore
new file mode 100644
index 000000000..cba7efc8e
--- /dev/null
+++ b/usrp2/fpga/control_lib/newfifo/.gitignore
@@ -0,0 +1 @@
+a.out
diff --git a/usrp2/fpga/control_lib/newfifo/fifo18_to_ll8.v b/usrp2/fpga/control_lib/newfifo/fifo18_to_ll8.v
deleted file mode 100644
index 4653244ef..000000000
--- a/usrp2/fpga/control_lib/newfifo/fifo18_to_ll8.v
+++ /dev/null
@@ -1,58 +0,0 @@
-
-module fifo18_to_ll8
-  (input clk, input reset, input clear,
-   input [35:0] f18_data,
-   input f18_src_rdy_i,
-   output f18_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);
-
-   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   f18_sof = f18_data[32];
-   wire   f18_eof = f18_data[33];
-   wire   f18_occ = f18_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 = f18_data[31:24];
-       1 : ll_data = f18_data[23:16];
-       2 : ll_data = f18_data[15:8];
-       3 : ll_data = f18_data[7:0];
-       default : ll_data = f18_data[31:24];
-       endcase // case (state)
-   
-   assign ll_sof 	 = (state==0) & f18_sof;
-   assign ll_eof 	 = f18_eof & (((state==0)&(f18_occ==1)) |
-			       ((state==1)&(f18_occ==2)) |
-			       ((state==2)&(f18_occ==3)) |
-			       (state==3));
-   
-   assign ll_src_rdy 	 = f18_src_rdy_i;
-
-   assign advance 	 = ll_src_rdy & ll_dst_rdy;
-   assign f18_dst_rdy_o  = advance & ((state==3)|ll_eof);
-   assign debug 	 = state;
-   
-endmodule // ll8_to_fifo36
diff --git a/usrp2/fpga/control_lib/newfifo/fifo36_to_ll8.v b/usrp2/fpga/control_lib/newfifo/fifo36_to_ll8.v
index 1befb9e6e..0dee1dfc6 100644
--- a/usrp2/fpga/control_lib/newfifo/fifo36_to_ll8.v
+++ b/usrp2/fpga/control_lib/newfifo/fifo36_to_ll8.v
@@ -1,6 +1,6 @@
 
 module fifo36_to_ll8
-  (input clk, reset,
+  (input clk, input reset, input clear,
    input [35:0] f36_data,
    input f36_src_rdy_i,
    output f36_dst_rdy_o,
diff --git a/usrp2/fpga/control_lib/newfifo/fifo_2clock.v b/usrp2/fpga/control_lib/newfifo/fifo_2clock.v
index 6b1eb607e..34c85ccb4 100644
--- a/usrp2/fpga/control_lib/newfifo/fifo_2clock.v
+++ b/usrp2/fpga/control_lib/newfifo/fifo_2clock.v
@@ -1,9 +1,58 @@
 
+// FIXME ignores the AWIDTH (fifo size) parameter
+
 module fifo_2clock
-  #(parameter DWIDTH=32, AWIDTH=9)
-    (input wclk, input [DWIDTH-1:0] datain, input write, output full, output reg [AWIDTH-1:0] level_wclk,
-     input rclk, output [DWIDTH-1:0] dataout, input read, output empty, output reg [AWIDTH-1:0] level_rclk,
-     input arst);
+  #(parameter WIDTH=36, SIZE=6)
+   (input wclk, input [WIDTH-1:0] datain, input src_rdy_i, output dst_rdy_o, output [15:0] space,
+    input rclk, output [WIDTH-1:0] dataout, output src_rdy_o, input dst_rdy_i, output [15:0] occupied,
+    input arst);
+   
+   wire [SIZE:0] level_rclk, level_wclk; // xilinx adds an extra bit if you ask for accurate levels
+   wire 	 full, empty, write, read;
+
+   assign dst_rdy_o  = ~full;
+   assign src_rdy_o  = ~empty;
+   assign write      = src_rdy_i & dst_rdy_o;
+   assign read 	     = src_rdy_o & dst_rdy_i;
+
+   generate
+      if(WIDTH==36)
+	if(SIZE==9)
+	  fifo_xlnx_512x36_2clk fifo_xlnx_512x36_2clk
+	       (.rst(arst),
+		.wr_clk(wclk),.din(datain),.full(full),.wr_en(write),.wr_data_count(level_wclk),
+		.rd_clk(rclk),.dout(dataout),.empty(empty),.rd_en(read),.rd_data_count(level_rclk) );
+	else if(SIZE==11)
+	  fifo_xlnx_2Kx36_2clk fifo_xlnx_2Kx36_2clk 
+		     (.rst(arst),
+		      .wr_clk(wclk),.din(datain),.full(full),.wr_en(write),.wr_data_count(level_wclk),
+		      .rd_clk(rclk),.dout(dataout),.empty(empty),.rd_en(read),.rd_data_count(level_rclk) );
+	else if(SIZE==6)
+	  fifo_xlnx_64x36_2clk fifo_xlnx_64x36_2clk 
+		     (.rst(arst),
+		      .wr_clk(wclk),.din(datain),.full(full),.wr_en(write),.wr_data_count(level_wclk),
+		      .rd_clk(rclk),.dout(dataout),.empty(empty),.rd_en(read),.rd_data_count(level_rclk) );
+	else
+	  fifo_xlnx_512x36_2clk fifo_xlnx_512x36_2clk
+	       (.rst(arst),
+		.wr_clk(wclk),.din(datain),.full(full),.wr_en(write),.wr_data_count(level_wclk),
+		.rd_clk(rclk),.dout(dataout),.empty(empty),.rd_en(read),.rd_data_count(level_rclk) );
+      else if((WIDTH==19)|(WIDTH==18))
+	if(SIZE==4)
+	  fifo_xlnx_16x19_2clk fifo_xlnx_16x19_2clk
+		     (.rst(arst),
+		      .wr_clk(wclk),.din(datain),.full(full),.wr_en(write),.wr_data_count(level_wclk),
+		      .rd_clk(rclk),.dout(dataout),.empty(empty),.rd_en(read),.rd_data_count(level_rclk) );
+   endgenerate
+   
+   assign occupied  = {{(16-SIZE-1){1'b0}},level_rclk};
+   assign space     = ((1<<SIZE)+1)-level_wclk;
+   
+endmodule // fifo_2clock
+
+/*
+`else
+   // ISE sucks, so the following doesn't work properly
 
    reg [AWIDTH-1:0] wr_addr, rd_addr;
    wire [AWIDTH-1:0] wr_addr_rclk, rd_addr_wclk;
@@ -62,5 +111,7 @@ module fifo_2clock
      level_wclk <= wr_addr - rd_addr_wclk;
    always @(posedge rclk) 
      level_rclk <= wr_addr_rclk - rd_addr;
-   
+`endif
 endmodule // fifo_2clock
+
+*/
diff --git a/usrp2/fpga/control_lib/newfifo/fifo_2clock_casc.v b/usrp2/fpga/control_lib/newfifo/fifo_2clock_casc.v
deleted file mode 100644
index e9b0cfc25..000000000
--- a/usrp2/fpga/control_lib/newfifo/fifo_2clock_casc.v
+++ /dev/null
@@ -1,31 +0,0 @@
-
-module fifo_2clock_casc
-  #(parameter DWIDTH=32, AWIDTH=9)
-    (input wclk, input [DWIDTH-1:0] datain, input write, output full, output [AWIDTH-1:0] level_wclk,
-     input rclk, output [DWIDTH-1:0] dataout, input read, output empty, output [AWIDTH-1:0] level_rclk,
-     input arst);
-
-   wire    full_int, empty_int, full_int2, empty_int2, transfer, transfer2;
-   wire [DWIDTH-1:0] data_int, data_int2;
-   
-   shortfifo #(.WIDTH(DWIDTH)) shortfifo
-     (.clk(wclk), .rst(arst), .clear(0),
-      .datain(datain), .write(write), .full(full),
-      .dataout(data_int), .read(transfer), .empty(empty_int) );
-
-   assign  transfer = ~full_int & ~empty_int;
-   
-   fifo_2clock #(.DWIDTH(DWIDTH),.AWIDTH(AWIDTH)) fifo_2clock
-     (.wclk(wclk), .datain(data_int), .write(transfer), .full(full_int), .level_wclk(level_wclk),
-      .rclk(rclk), .dataout(data_int2), .read(transfer2), .empty(empty_int2), .level_rclk(level_rclk),
-      .arst(arst) );
-
-   assign  transfer2 = ~full_int2 & ~empty_int2;
-
-   shortfifo #(.WIDTH(DWIDTH)) shortfifo2
-     (.clk(rclk), .rst(arst), .clear(0),
-      .datain(data_int2), .write(transfer2), .full(full_int2),
-      .dataout(dataout), .read(read), .empty(empty) );
-   
-endmodule // fifo_2clock_casc
-
diff --git a/usrp2/fpga/control_lib/newfifo/fifo_2clock_cascade.v b/usrp2/fpga/control_lib/newfifo/fifo_2clock_cascade.v
new file mode 100644
index 000000000..5ce726977
--- /dev/null
+++ b/usrp2/fpga/control_lib/newfifo/fifo_2clock_cascade.v
@@ -0,0 +1,35 @@
+
+module fifo_2clock_cascade
+  #(parameter WIDTH=32, SIZE=9)
+   (input wclk, input [WIDTH-1:0] datain, input src_rdy_i, output dst_rdy_o, output [15:0] space,
+    input rclk, output [WIDTH-1:0] dataout, output src_rdy_o, input dst_rdy_i, output [15:0] occupied,
+    input arst);
+   
+   wire [WIDTH-1:0] data_int1, data_int2;
+   wire 	    src_rdy_int1, src_rdy_int2, dst_rdy_int1, dst_rdy_int2;
+   wire [SIZE-1:0]  level_wclk, level_rclk;
+   wire [4:0] 	    s1_space, s1_occupied, s2_space, s2_occupied;
+   wire [15:0] 	    l_space, l_occupied;
+   
+   fifo_short #(.WIDTH(WIDTH)) shortfifo
+     (.clk(wclk), .reset(arst), .clear(0),
+      .datain(datain), .src_rdy_i(src_rdy_i), .dst_rdy_o(dst_rdy_o),
+      .dataout(data_int1), .src_rdy_o(src_rdy_int1), .dst_rdy_i(dst_rdy_int1),
+      .space(s1_space), .occupied(s1_occupied) );
+   
+   fifo_2clock #(.WIDTH(WIDTH),.SIZE(SIZE)) fifo_2clock
+     (.wclk(wclk), .datain(data_int1), .src_rdy_i(src_rdy_int1), .dst_rdy_o(dst_rdy_int1), .space(l_space),
+      .rclk(rclk), .dataout(data_int2), .src_rdy_o(src_rdy_int2), .dst_rdy_i(dst_rdy_int2), .occupied(l_occupied),
+      .arst(arst) );
+   
+   fifo_short #(.WIDTH(WIDTH)) shortfifo2
+     (.clk(rclk), .reset(arst), .clear(0),
+      .datain(data_int2), .src_rdy_i(src_rdy_int2), .dst_rdy_o(dst_rdy_int2),
+      .dataout(dataout), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i),
+      .space(s2_space), .occupied(s2_occupied));
+
+   // Be conservative -- Only advertise space from input side of fifo, occupied from output side
+   assign 	    space = {11'b0,s1_space} + l_space;
+   assign 	    occupied = {11'b0,s2_occupied} + l_occupied;
+   
+endmodule // fifo_2clock_cascade
diff --git a/usrp2/fpga/control_lib/newfifo/fifo_new_tb.v b/usrp2/fpga/control_lib/newfifo/fifo_new_tb.v
deleted file mode 100644
index f561df7fa..000000000
--- a/usrp2/fpga/control_lib/newfifo/fifo_new_tb.v
+++ /dev/null
@@ -1,158 +0,0 @@
-module fifo_new_tb();
-   
-   reg clk = 0;
-   reg rst = 1;
-   reg clear = 0;
-   initial #1000 rst = 0;
-   always #50 clk = ~clk;
-   
-   reg [31:0] f36_data = 0;
-   reg [1:0] f36_occ = 0;
-   reg f36_sof = 0, f36_eof = 0;
-   
-   wire [35:0] f36_in = {f36_occ,f36_eof,f36_sof,f36_data};
-   reg src_rdy_f36i  = 0;
-   wire dst_rdy_f36i;
-
-   wire [35:0] f36_out, f36_out2;
-   wire src_rdy_f36o;
-   reg dst_rdy_f36o  = 0;
-   
-   //fifo_cascade #(.WIDTH(36), .SIZE(4)) fifo_cascade36
-   //fifo_long #(.WIDTH(36), .SIZE(4)) fifo_cascade36
-
-   wire i1_sr, i1_dr;
-   wire i2_sr, i2_dr;
-   wire i3_sr, i3_dr;
-   reg i4_dr = 0;
-   wire i4_sr;
-      
-   wire [35:0] i1, i4;
-   wire [18:0] i2, i3;
-   
-   wire [7:0] ll_data;
-   wire ll_src_rdy_n, ll_dst_rdy_n, ll_sof_n, ll_eof_n;
-   
-   fifo_short #(.WIDTH(36)) fifo_short1
-     (.clk(clk),.reset(rst),.clear(clear),
-      .datain(f36_in),.src_rdy_i(src_rdy_f36i),.dst_rdy_o(dst_rdy_f36i),
-      .dataout(i1),.src_rdy_o(i1_sr),.dst_rdy_i(i1_dr) );
-
-   fifo36_to_fifo19 fifo36_to_fifo19
-     (.clk(clk),.reset(rst),.clear(clear),
-      .f36_datain(i1),.f36_src_rdy_i(i1_sr),.f36_dst_rdy_o(i1_dr),
-      .f19_dataout(i2),.f19_src_rdy_o(i2_sr),.f19_dst_rdy_i(i2_dr) );
-
-   fifo19_to_ll8 fifo19_to_ll8
-     (.clk(clk),.reset(rst),.clear(clear),
-      .f19_data(i2),.f19_src_rdy_i(i2_sr),.f19_dst_rdy_o(i2_dr),
-      .ll_data(ll_data),.ll_sof_n(ll_sof_n),.ll_eof_n(ll_eof_n),
-      .ll_src_rdy_n(ll_src_rdy_n),.ll_dst_rdy_n(ll_dst_rdy_n));
-
-   ll8_to_fifo19 ll8_to_fifo19
-     (.clk(clk),.reset(rst),.clear(clear),
-      .ll_data(ll_data),.ll_sof_n(ll_sof_n),.ll_eof_n(ll_eof_n),
-      .ll_src_rdy_n(ll_src_rdy_n),.ll_dst_rdy_n(ll_dst_rdy_n),
-      .f19_data(i3),.f19_src_rdy_o(i3_sr),.f19_dst_rdy_i(i3_dr) );
-
-   fifo19_to_fifo36 fifo19_to_fifo36
-     (.clk(clk),.reset(rst),.clear(clear),
-      .f19_datain(i3),.f19_src_rdy_i(i3_sr),.f19_dst_rdy_o(i3_dr),
-      .f36_dataout(i4),.f36_src_rdy_o(i4_sr),.f36_dst_rdy_i(i4_dr) );
-     
-   task ReadFromFIFO36;
-      begin
-	 $display("Read from FIFO36");
-	 #1 i4_dr <= 1;
-	 while(1)
-	   begin
-	      while(~i4_sr)
-		@(posedge clk);
-	      $display("Read: %h",i4);
-	      @(posedge clk);
-	   end
-      end
-   endtask // ReadFromFIFO36
-
-   reg [15:0] count;
-   task PutPacketInFIFO36;
-      input [31:0] data_start;
-      input [31:0] data_len;
-      begin
-	 count 	      <= 4;
-	 src_rdy_f36i <= 1;
-	 f36_data     <= data_start;
-	 f36_sof      <= 1;
-	 f36_eof      <= 0;
-	 f36_occ      <= 0;
-	
-	 $display("Put Packet in FIFO36");
-	 while(~dst_rdy_f36i)
-	   @(posedge clk);
-	 @(posedge clk);
-	 $display("PPI_FIFO36: Entered First Line");
-	 f36_sof <= 0;
-	 while(count+4 < data_len)
-	   begin
-	      f36_data <= f36_data + 32'h01010101;
-	      count    <= count + 4;
-	      while(~dst_rdy_f36i)
-		@(posedge clk);
-	      @(posedge clk);
-	      $display("PPI_FIFO36: Entered New Line");
-	   end
-	 f36_data  <= f36_data + 32'h01010101;
-	 f36_eof   <= 1;
-	 if(count + 4 == data_len)
-	   f36_occ <= 0;
-	 else if(count + 3 == data_len)
-	   f36_occ <= 3;
-	 else if(count + 2 == data_len)
-	   f36_occ <= 2;
-	 else
-	   f36_occ <= 1;
-	 while(~dst_rdy_f36i)
-	   @(posedge clk);
-	 @(posedge clk);
-	 f36_occ      <= 0;
-	 f36_eof      <= 0;
-	 f36_data     <= 0;
-	 src_rdy_f36i <= 0;
-	 $display("PPI_FIFO36: Entered Last Line");
-      end
-   endtask // PutPacketInFIFO36
-   
-   initial $dumpfile("fifo_new_tb.vcd");
-   initial $dumpvars(0,fifo_new_tb);
-
-   initial
-     begin
-	@(negedge rst);
-	//#10000;
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	ReadFromFIFO36;
-     end
-   
-   initial
-     begin
-	@(negedge rst);
-	@(posedge clk);
-	@(posedge clk);
-	PutPacketInFIFO36(32'hA0B0C0D0,12);
-	@(posedge clk);
-	@(posedge clk);
-	#10000;
-	@(posedge clk);
-	PutPacketInFIFO36(32'hE0F0A0B0,36);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-     end
-
-   initial #20000 $finish;
-endmodule // longfifo_tb
diff --git a/usrp2/fpga/control_lib/newfifo/fifo_tb.v b/usrp2/fpga/control_lib/newfifo/fifo_tb.v
index 98fd63f8d..f561df7fa 100644
--- a/usrp2/fpga/control_lib/newfifo/fifo_tb.v
+++ b/usrp2/fpga/control_lib/newfifo/fifo_tb.v
@@ -1,155 +1,158 @@
-module fifo_tb();
+module fifo_new_tb();
    
-   reg clk, rst;
-   wire short_full, short_empty, long_full, long_empty;
-   wire casc_full, casc_empty, casc2_full, casc2_empty;
-   reg 	read, write;
-   
-   wire [7:0] short_do, long_do;
-   wire [7:0] casc_do, casc2_do;
-   reg [7:0]  di;
-
-   reg 	      clear = 0;
-   
-   shortfifo #(.WIDTH(8)) shortfifo
-     (.clk(clk),.rst(rst),.datain(di),.dataout(short_do),.clear(clear),
-      .read(read),.write(write),.full(short_full),.empty(short_empty));
+   reg clk = 0;
+   reg rst = 1;
+   reg clear = 0;
+   initial #1000 rst = 0;
+   always #50 clk = ~clk;
    
-   longfifo #(.WIDTH(8), .SIZE(4)) longfifo
-     (.clk(clk),.rst(rst),.datain(di),.dataout(long_do),.clear(clear),
-      .read(read),.write(write),.full(long_full),.empty(long_empty));
+   reg [31:0] f36_data = 0;
+   reg [1:0] f36_occ = 0;
+   reg f36_sof = 0, f36_eof = 0;
    
-   cascadefifo #(.WIDTH(8), .SIZE(4)) cascadefifo
-     (.clk(clk),.rst(rst),.datain(di),.dataout(casc_do),.clear(clear),
-      .read(read),.write(write),.full(casc_full),.empty(casc_empty));
+   wire [35:0] f36_in = {f36_occ,f36_eof,f36_sof,f36_data};
+   reg src_rdy_f36i  = 0;
+   wire dst_rdy_f36i;
+
+   wire [35:0] f36_out, f36_out2;
+   wire src_rdy_f36o;
+   reg dst_rdy_f36o  = 0;
    
-   cascadefifo2 #(.WIDTH(8), .SIZE(4)) cascadefifo2
-     (.clk(clk),.rst(rst),.datain(di),.dataout(casc2_do),.clear(clear),
-      .read(read),.write(write),.full(casc2_full),.empty(casc2_empty));
+   //fifo_cascade #(.WIDTH(36), .SIZE(4)) fifo_cascade36
+   //fifo_long #(.WIDTH(36), .SIZE(4)) fifo_cascade36
+
+   wire i1_sr, i1_dr;
+   wire i2_sr, i2_dr;
+   wire i3_sr, i3_dr;
+   reg i4_dr = 0;
+   wire i4_sr;
+      
+   wire [35:0] i1, i4;
+   wire [18:0] i2, i3;
    
-   initial rst = 1;
-   initial #1000 rst = 0;
-   initial clk = 0;
-   always #50 clk = ~clk;
+   wire [7:0] ll_data;
+   wire ll_src_rdy_n, ll_dst_rdy_n, ll_sof_n, ll_eof_n;
    
-   initial di = 8'hAE;
-   initial read = 0;
-   initial write = 0;
+   fifo_short #(.WIDTH(36)) fifo_short1
+     (.clk(clk),.reset(rst),.clear(clear),
+      .datain(f36_in),.src_rdy_i(src_rdy_f36i),.dst_rdy_o(dst_rdy_f36i),
+      .dataout(i1),.src_rdy_o(i1_sr),.dst_rdy_i(i1_dr) );
 
-   always @(posedge clk)
-     if(write)
-       di <= di + 1;
-   
-   always @(posedge clk)
-     begin
-	if(short_full != long_full)
-	  $display("Error: FULL mismatch");
-	if(short_empty != long_empty)
-	  $display("Note: EMPTY mismatch, usually not a problem (longfifo has 2 cycle latency)");
-	if(read & (short_do != long_do))
-	  $display("Error: DATA mismatch");
-     end
+   fifo36_to_fifo19 fifo36_to_fifo19
+     (.clk(clk),.reset(rst),.clear(clear),
+      .f36_datain(i1),.f36_src_rdy_i(i1_sr),.f36_dst_rdy_o(i1_dr),
+      .f19_dataout(i2),.f19_src_rdy_o(i2_sr),.f19_dst_rdy_i(i2_dr) );
+
+   fifo19_to_ll8 fifo19_to_ll8
+     (.clk(clk),.reset(rst),.clear(clear),
+      .f19_data(i2),.f19_src_rdy_i(i2_sr),.f19_dst_rdy_o(i2_dr),
+      .ll_data(ll_data),.ll_sof_n(ll_sof_n),.ll_eof_n(ll_eof_n),
+      .ll_src_rdy_n(ll_src_rdy_n),.ll_dst_rdy_n(ll_dst_rdy_n));
+
+   ll8_to_fifo19 ll8_to_fifo19
+     (.clk(clk),.reset(rst),.clear(clear),
+      .ll_data(ll_data),.ll_sof_n(ll_sof_n),.ll_eof_n(ll_eof_n),
+      .ll_src_rdy_n(ll_src_rdy_n),.ll_dst_rdy_n(ll_dst_rdy_n),
+      .f19_data(i3),.f19_src_rdy_o(i3_sr),.f19_dst_rdy_i(i3_dr) );
+
+   fifo19_to_fifo36 fifo19_to_fifo36
+     (.clk(clk),.reset(rst),.clear(clear),
+      .f19_datain(i3),.f19_src_rdy_i(i3_sr),.f19_dst_rdy_o(i3_dr),
+      .f36_dataout(i4),.f36_src_rdy_o(i4_sr),.f36_dst_rdy_i(i4_dr) );
+     
+   task ReadFromFIFO36;
+      begin
+	 $display("Read from FIFO36");
+	 #1 i4_dr <= 1;
+	 while(1)
+	   begin
+	      while(~i4_sr)
+		@(posedge clk);
+	      $display("Read: %h",i4);
+	      @(posedge clk);
+	   end
+      end
+   endtask // ReadFromFIFO36
+
+   reg [15:0] count;
+   task PutPacketInFIFO36;
+      input [31:0] data_start;
+      input [31:0] data_len;
+      begin
+	 count 	      <= 4;
+	 src_rdy_f36i <= 1;
+	 f36_data     <= data_start;
+	 f36_sof      <= 1;
+	 f36_eof      <= 0;
+	 f36_occ      <= 0;
+	
+	 $display("Put Packet in FIFO36");
+	 while(~dst_rdy_f36i)
+	   @(posedge clk);
+	 @(posedge clk);
+	 $display("PPI_FIFO36: Entered First Line");
+	 f36_sof <= 0;
+	 while(count+4 < data_len)
+	   begin
+	      f36_data <= f36_data + 32'h01010101;
+	      count    <= count + 4;
+	      while(~dst_rdy_f36i)
+		@(posedge clk);
+	      @(posedge clk);
+	      $display("PPI_FIFO36: Entered New Line");
+	   end
+	 f36_data  <= f36_data + 32'h01010101;
+	 f36_eof   <= 1;
+	 if(count + 4 == data_len)
+	   f36_occ <= 0;
+	 else if(count + 3 == data_len)
+	   f36_occ <= 3;
+	 else if(count + 2 == data_len)
+	   f36_occ <= 2;
+	 else
+	   f36_occ <= 1;
+	 while(~dst_rdy_f36i)
+	   @(posedge clk);
+	 @(posedge clk);
+	 f36_occ      <= 0;
+	 f36_eof      <= 0;
+	 f36_data     <= 0;
+	 src_rdy_f36i <= 0;
+	 $display("PPI_FIFO36: Entered Last Line");
+      end
+   endtask // PutPacketInFIFO36
    
-   initial $dumpfile("fifo_tb.vcd");
-   initial $dumpvars(0,fifo_tb);
+   initial $dumpfile("fifo_new_tb.vcd");
+   initial $dumpvars(0,fifo_new_tb);
 
    initial
      begin
 	@(negedge rst);
-	@(posedge clk);
-	repeat (10)
-	  @(posedge clk);
-	write <= 1;
-	@(posedge clk);
-	write <= 0;
-	@(posedge clk);
-	@(posedge clk);
+	//#10000;
 	@(posedge clk);
 	@(posedge clk);
 	@(posedge clk);
 	@(posedge clk);
+	ReadFromFIFO36;
+     end
+   
+   initial
+     begin
+	@(negedge rst);
 	@(posedge clk);
 	@(posedge clk);
-	read <= 1;
-	@(posedge clk);
-	read <= 0;
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-	@(posedge clk);
-
-	repeat(10)
-	  begin
-	     write <= 1;
-	     @(posedge clk);
-	     write <= 0;
-	     @(posedge clk);
-	     @(posedge clk);
-	     @(posedge clk);
-	     read <= 1;
-	     @(posedge clk);
-	     read <= 0;
-	     @(posedge clk);
-	     @(posedge clk);
-	     @(posedge clk);
-	     @(posedge clk);
-	     @(posedge clk);
-	  end // repeat (10)
-	
-	write <= 1;
-	repeat (4)
-	  @(posedge clk);
-	write <= 0;
-	@(posedge clk);
-	read <= 1;
-	repeat (4)
-	  @(posedge clk);
-	read <= 0;
-	@(posedge clk);
-
-
-	write <= 1;
-	repeat (4)
-	  @(posedge clk);
-	write <= 0;
+	PutPacketInFIFO36(32'hA0B0C0D0,12);
 	@(posedge clk);
-	repeat (4)
-	  begin
-	     read <= 1;
-	     @(posedge clk);
-	     read <= 0;
-	     @(posedge clk);
-	  end
-
-	write <= 1;
 	@(posedge clk);
+	#10000;
 	@(posedge clk);
+	PutPacketInFIFO36(32'hE0F0A0B0,36);
 	@(posedge clk);
 	@(posedge clk);
-	read <= 1;
-	repeat (5)
-	  @(posedge clk);
-	write <= 0;
-	  @(posedge clk);
-	  @(posedge clk);
-	read <= 0;
 	@(posedge clk);
-
-	write <= 1;
-	repeat (16)
-	  @(posedge clk);
-	write <= 0;
 	@(posedge clk);
-	
-	read <= 1;
-	repeat (16)
-	  @(posedge clk);
-	read <= 0;
 	@(posedge clk);
-		 
-	repeat (10)
-	  @(posedge clk);
-	$finish;
      end
+
+   initial #20000 $finish;
 endmodule // longfifo_tb
diff --git a/usrp2/fpga/control_lib/newfifo/ll8_shortfifo.v b/usrp2/fpga/control_lib/newfifo/ll8_shortfifo.v
new file mode 100644
index 000000000..39ada9a4f
--- /dev/null
+++ b/usrp2/fpga/control_lib/newfifo/ll8_shortfifo.v
@@ -0,0 +1,13 @@
+
+
+module ll8_shortfifo
+  (input clk, input reset, input clear,
+   input [7:0] datain, input sof_i, input eof_i, input error_i, input src_rdy_i, output dst_rdy_o,
+   output [7:0] dataout, output sof_o, output eof_o, output error_o, output src_rdy_o, input dst_rdy_i);
+
+   fifo_short #(.WIDTH(11)) fifo_short
+     (.clk(clk), .reset(reset), .clear(clear),
+      .datain({error_i,eof_i,sof_i,datain}), .src_rdy_i(src_rdy_i), .dst_rdy_o(dst_rdy_o),
+      .dataout({error_o,eof_o,sof_o,dataout}), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i));
+
+endmodule // ll8_shortfifo