Merge FPGA repository back into UHD repository

The FPGA codebase was removed from the UHD repository in 2014 to reduce
the size of the repository. However, over the last half-decade, the
split between the repositories has proven more burdensome than it has
been helpful. By merging the FPGA code back, it will be possible to
create atomic commits that touch both FPGA and UHD codebases. Continuous
integration testing is also simplified by merging the repositories,
because it was previously difficult to automatically derive the correct
UHD branch when testing a feature branch on the FPGA repository.

This commit also updates the license files and paths therein.

We are therefore merging the repositories again. Future development for
FPGA code will happen in the same repository as the UHD host code and
MPM code.

== Original Codebase and Rebasing ==

The original FPGA repository will be hosted for the foreseeable future
at its original local location: https://github.com/EttusResearch/fpga/

It can be used for bisecting, reference, and a more detailed history.

The final commit from said repository to be merged here is
05003794e2da61cabf64dd278c45685a7abad7ec. This commit is tagged as
v4.0.0.0-pre-uhd-merge.

If you have changes in the FPGA repository that you want to rebase onto
the UHD repository, simply run the following commands:

- Create a directory to store patches (this should be an empty
  directory):

    mkdir ~/patches

- Now make sure that your FPGA codebase is based on the same state as
  the code that was merged:

    cd src/fpga # Or wherever your FPGA code is stored
    git rebase v4.0.0.0-pre-uhd-merge

  Note: The rebase command may look slightly different depending on what
  exactly you're trying to rebase.

- Create a patch set for your changes versus v4.0.0.0-pre-uhd-merge:

    git format-patch v4.0.0.0-pre-uhd-merge -o ~/patches

  Note: Make sure that only patches are stored in your output directory.
  It should otherwise be empty. Make sure that you picked the correct
  range of commits, and only commits you wanted to rebase were exported
  as patch files.

- Go to the UHD repository and apply the patches:

    cd src/uhd # Or wherever your UHD repository is stored
    git am --directory fpga ~/patches/*
    rm -rf ~/patches # This is for cleanup

== Contributors ==

The following people have contributed mainly to these files (this list
is not complete):

Co-authored-by: Alex Williams <alex.williams@ni.com>
Co-authored-by: Andrej Rode <andrej.rode@ettus.com>
Co-authored-by: Ashish Chaudhari <ashish@ettus.com>
Co-authored-by: Ben Hilburn <ben.hilburn@ettus.com>
Co-authored-by: Ciro Nishiguchi <ciro.nishiguchi@ni.com>
Co-authored-by: Daniel Jepson <daniel.jepson@ni.com>
Co-authored-by: Derek Kozel <derek.kozel@ettus.com>
Co-authored-by: EJ Kreinar <ej@he360.com>
Co-authored-by: Humberto Jimenez <humberto.jimenez@ni.com>
Co-authored-by: Ian Buckley <ian.buckley@gmail.com>
Co-authored-by: Jörg Hofrichter <joerg.hofrichter@ni.com>
Co-authored-by: Jon Kiser <jon.kiser@ni.com>
Co-authored-by: Josh Blum <josh@joshknows.com>
Co-authored-by: Jonathon Pendlum <jonathan.pendlum@ettus.com>
Co-authored-by: Martin Braun <martin.braun@ettus.com>
Co-authored-by: Matt Ettus <matt@ettus.com>
Co-authored-by: Michael West <michael.west@ettus.com>
Co-authored-by: Moritz Fischer <moritz.fischer@ettus.com>
Co-authored-by: Nick Foster <nick@ettus.com>
Co-authored-by: Nicolas Cuervo <nicolas.cuervo@ettus.com>
Co-authored-by: Paul Butler <paul.butler@ni.com>
Co-authored-by: Paul David <paul.david@ettus.com>
Co-authored-by: Ryan Marlow <ryan.marlow@ettus.com>
Co-authored-by: Sugandha Gupta <sugandha.gupta@ettus.com>
Co-authored-by: Sylvain Munaut <tnt@246tNt.com>
Co-authored-by: Trung Tran <trung.tran@ettus.com>
Co-authored-by: Vidush Vishwanath <vidush.vishwanath@ettus.com>
Co-authored-by: Wade Fife <wade.fife@ettus.com>

1 files changed, 435 insertions, 0 deletions

diff --git a/fpga/usrp2/fifo/buffer_int_tb.v b/fpga/usrp2/fifo/buffer_int_tb.v
new file mode 100644
index 000000000..44f8be0a0
--- /dev/null
+++ b/fpga/usrp2/fifo/buffer_int_tb.v
@@ -0,0 +1,435 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+
+module buffer_int_tb ();
+
+   reg clk = 0;
+   reg rst = 1;
+
+   initial #100 rst = 0;
+   always #5 clk = ~clk;
+
+   wire en, we;
+   wire [8:0] addr;
+   wire [31:0] fifo2buf, buf2fifo;
+   
+   wire [31:0] rd_data_o;
+   wire [3:0]  rd_flags_o;
+   wire        rd_sop_o, rd_eop_o;
+   reg 	       rd_error_i = 0, rd_read_i = 0;
+   
+   reg [31:0]  wr_data_i = 0;
+   wire [3:0]  wr_flags_i;
+   reg 	       wr_eop_i = 0, wr_sop_i = 0;
+   reg 	       wr_write_i = 0;
+   wire        wr_ready_o, wr_full_o;
+   
+   reg 	       clear = 0, write = 0, read = 0;
+   reg [8:0]   firstline = 0, lastline = 0;
+   wire [3:0]  step = 1;
+   wire [31:0] ctrl_word = {4'b0,3'b0,clear,write,read,step,lastline,firstline};
+   reg 	       go = 0;
+   wire        done, error;
+
+   assign      wr_flags_i = {2'b00, wr_eop_i, wr_sop_i};
+   assign      rd_sop_o = rd_flags_o[0];
+   assign      rd_eop_o = rd_flags_o[1];
+   
+   buffer_int buffer_int
+     (.clk(clk),.rst(rst),
+      .ctrl_word(ctrl_word),.go(go),
+      .done(done),.error(error),
+      
+      // Buffer Interface
+      .en_o(en),.we_o(we),.addr_o(addr),
+      .dat_to_buf(fifo2buf),.dat_from_buf(buf2fifo),
+
+      // Write FIFO Interface
+      .wr_data_i(wr_data_i), .wr_flags_i(wr_flags_i), .wr_write_i(wr_write_i), .wr_ready_o(wr_ready_o),
+
+      // Read FIFO Interface
+      .rd_data_o(rd_data_o), .rd_flags_o(rd_flags_o), .rd_ready_o(rd_ready_o), .rd_read_i(rd_read_i)
+      );
+   
+   reg 	       ram_en = 0, ram_we = 0;
+   reg [8:0]   ram_addr = 0;
+   reg [31:0]  ram_data = 0;
+   
+   ram_2port #(.DWIDTH(32),.AWIDTH(9)) ram_2port
+     (.clka(clk), .ena(ram_en), .wea(ram_we), .addra(ram_addr), .dia(ram_data), .doa(),
+      .clkb(clk), .enb(en), .web(we), .addrb(addr), .dib(fifo2buf), .dob(buf2fifo) );
+   
+   initial
+     begin
+	@(negedge rst);
+	@(posedge clk);
+	FillRAM;
+
+	ResetBuffer;
+	SetBufferRead(5,10);
+	$display("Testing full read, no wait states.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(6,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(5,10);
+	$display("Testing full read, 2 wait states.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(6,2);
+	repeat (10)
+	  @(posedge clk);
+
+	ResetBuffer;
+	SetBufferRead(5,10);
+	$display("Testing partial read, 0 wait states, then nothing after last.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(3,0);
+	repeat (10)
+	  @(posedge clk);
+
+	ResetBuffer;
+	SetBufferRead(5,10);
+	$display("Testing partial read, 0 wait states, then done at same time as last.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(2,0);
+	ReadALine;
+	repeat (10)
+	  @(posedge clk);
+
+	ResetBuffer;
+	SetBufferRead(5,10);
+	$display("Testing partial read, 3 wait states, then error at same time as last.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(2,3);
+	rd_error_i <= 1;
+	ReadALine;
+	rd_error_i <= 0;
+	repeat (10)
+	  @(posedge clk);
+
+	ResetBuffer;
+	SetBufferRead(500,511);
+	$display("Testing full read, to the end of the buffer.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(12,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(0,511);
+	$display("Testing full read, start to end of the buffer.");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(512,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(505,3);
+	$display("Testing full read, wraparound");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(11,0);
+	repeat (10)
+	  @(posedge clk);
+
+	ResetBuffer;
+	SetBufferWrite(10,15);
+	$display("Testing Full Write, no wait states");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(6,0,72);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(18,23);
+	$display("Testing Full Write, 1 wait states");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(6,1,101);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(27,40);
+	$display("Testing Partial Write, 0 wait states");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(6,0,201);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(45,200);
+	$display("Testing Partial Write, 0 wait states, then done and write simultaneously");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	wr_sop_i <= 1; wr_eop_i <= 0;
+	WriteLines(6,0,301);
+	wr_sop_i <= 0; wr_eop_i <= 1;
+	WriteALine(400);
+	wr_sop_i <= 0; wr_eop_i <= 0;
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(55,200);
+	$display("Testing Partial Write, 0 wait states, then error");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(6,0,501);
+	wr_sop_i <= 1; wr_eop_i <= 1;
+	WriteALine(400);
+	@(posedge clk);
+	repeat (10)
+	  @(posedge clk);
+	wr_sop_i <= 0; wr_eop_i <= 0;
+	
+	ResetBuffer;
+	SetBufferRead(0,82);
+	$display("Testing read after all the writes");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(83,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(508,4);
+	$display("Testing wraparound write");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(9,0,601);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(506,10);
+	$display("Reading wraparound write");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(17,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferWrite(0,511);
+	$display("Testing Whole Buffer write");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(512,0,1000);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(0,511);
+	$display("Reading Whole Buffer write");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(512,0);
+	repeat (10)
+	  @(posedge clk);
+
+	/*
+	ResetBuffer;
+	SetBufferWrite(5,10);
+	$display("Testing Write Too Many");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	WriteLines(12,0,2000);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(0,15);
+	$display("Reading back Write Too Many");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(16,0);
+	repeat (10)
+	  @(posedge clk);
+	*/
+	ResetBuffer;
+	SetBufferWrite(15,20);
+	$display("Testing Write One Less Than Full");
+	while(!wr_ready_o)
+	  @(posedge clk);
+	wr_sop_i <= 1; wr_eop_i <= 0;
+	WriteALine(400);
+	wr_sop_i <= 0; wr_eop_i <= 0;
+	WriteLines(3,0,2000);
+	wr_sop_i <= 0; wr_eop_i <= 1;
+	WriteALine(400);
+	wr_sop_i <= 0; wr_eop_i <= 0;
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	SetBufferRead(13,22);
+	$display("Reading back Write One Less Than Full");
+	while(!rd_sop_o)
+	  @(posedge clk);
+	ReadLines(10,0);
+	repeat (10)
+	  @(posedge clk);
+	
+	ResetBuffer;
+	repeat(100)
+	  @(posedge clk);
+	$finish;
+     end
+   
+   always @(posedge clk)
+     if(rd_read_i == 1'd1)
+       $display("READ Buffer %d, rd_sop_o %d, rd_eop_o %d", rd_data_o, rd_sop_o, rd_eop_o);
+
+   always @(posedge clk)
+     if(wr_write_i == 1'd1)
+       $display("WRITE Buffer %d,  wr_ready_o %d, wr_full_o %d", wr_data_i, wr_ready_o, wr_full_o);
+	   
+   initial begin
+      $dumpfile("buffer_int_tb.lxt");
+      $dumpvars(0,buffer_int_tb);
+   end
+
+   task FillRAM;
+      begin
+	 ram_addr <= 0;
+	 ram_data <= 0;
+	 @(posedge clk);
+	 ram_en <= 1;
+	 ram_we <= 1;
+	 @(posedge clk);
+	 repeat (511)
+	   begin
+	      ram_addr <= ram_addr + 1;
+	      ram_data <= ram_data + 1;
+	      ram_en <= 1;
+	      ram_we <= 1;
+	      @(posedge clk);
+	   end
+	 ram_en <= 0;
+	 ram_we <= 0;
+	 @(posedge clk);
+	 $display("Filled the RAM");
+      end
+   endtask // FillRAM
+
+   task ResetBuffer;
+      begin
+	 clear <= 1; read <= 0; write <= 0;
+	 go <= 1;
+	 @(posedge clk);
+	 go <= 0;
+	 @(posedge clk);
+	 $display("Buffer Reset");
+      end
+   endtask // ClearBuffer
+   
+   task SetBufferWrite;
+      input [8:0] start;
+      input [8:0] stop;
+      begin
+	 clear <= 0; read <= 0; write <= 1;
+	 firstline <= start;
+	 lastline <= stop;
+	 go <= 1;
+	 @(posedge clk);
+	 go <= 0;
+	 @(posedge clk);
+	 $display("Buffer Set for Write");
+      end
+   endtask // SetBufferWrite
+   
+   task SetBufferRead;
+      input [8:0] start;
+      input [8:0] stop;
+      begin
+	 clear <= 0; read <= 1; write <= 0;
+	 firstline <= start;
+	 lastline <= stop;
+	 go <= 1;
+	 @(posedge clk);
+	 go <= 0;
+	 @(posedge clk);
+	 $display("Buffer Set for Read");
+      end
+   endtask // SetBufferRead
+
+   task ReadALine;
+      begin
+	 while(~rd_ready_o)
+	   @(posedge clk);
+	 #1 rd_read_i <= 1;
+	 @(posedge clk);
+	 rd_read_i <= 0;
+      end
+   endtask // ReadALine
+
+   task ReadLines;
+      input [9:0] lines;
+      input [7:0] wait_states;
+      begin
+	 $display("Read Lines: Number %d, Wait States %d",lines,wait_states);
+	 repeat (lines)
+	   begin
+	      ReadALine;
+	      repeat (wait_states)
+		@(posedge clk);
+	   end
+      end
+   endtask // ReadLines
+   
+   task WriteALine;
+      input [31:0] value;
+      begin
+	 while(~wr_ready_o)
+	   @(posedge clk);
+	 #1 wr_write_i <= 1;
+	 wr_data_i <= value;
+	 @(posedge clk);
+	 wr_write_i <= 0;
+      end
+   endtask // WriteALine
+   
+   task WriteLines;
+      input [9:0] lines;
+      input [7:0] wait_states;
+      input [31:0] value;
+      begin
+	 $display("Write Lines: Number %d, Wait States %d",lines,wait_states);
+	 repeat(lines)
+	   begin
+	      value <= value + 1;
+	      WriteALine(value);
+	      repeat(wait_states)
+		@(posedge clk);
+	   end
+      end
+   endtask // WriteLines
+   
+endmodule // buffer_int_tb