fpga: lib: Add synthesizable AXI4-Stream SV components

Components are connected together with AxiStreamIfc. Some features
include:
  (1) Add bytes to the start of a packet
  (2) Remove bytes from a packet
  (3) Wrappers for some older components
      a.  fifo - buffer but imediately pass a packet
      b.  packet_gate - buffer and hold till end of packet
      c.  width_conv - cross clock domains and change width of axi bus

The AxiStreamIf was moved from PkgAxiStreamBfm to its own file. It can
be used to connect to ports with continuous assignment.
AxiStreamPacketIf must be used procedurally but allows the following
new methods:
  - reached_packet_byte - notify when tdata contains a paritcular byte
  - get_packet_byte/get_packet_field - extract a byte or field from axi
  - put_packet_byte/put_packet_field - overwrite a byte or field onto axi

1 files changed, 170 insertions, 69 deletions

diff --git a/fpga/usrp3/sim/rfnoc/PkgAxiStreamBfm.sv b/fpga/usrp3/sim/rfnoc/PkgAxiStreamBfm.sv
index 9e2530350..fd23e501c 100644
--- a/fpga/usrp3/sim/rfnoc/PkgAxiStreamBfm.sv
+++ b/fpga/usrp3/sim/rfnoc/PkgAxiStreamBfm.sv
@@ -1,61 +1,79 @@
 //
-// Copyright 2019 Ettus Research, A National Instruments Company
+// Copyright 2020 Ettus Research, A National Instruments Brand
 //
 // SPDX-License-Identifier: LGPL-3.0-or-later
 //
-// Module: PkgAxiStream
+// Module: PkgAxiStreamBfm
 //
-// Description: Package for a bi-directional AXI Stream bus functional model 
-// (BFM). This consists of the AxiStreamIf interface, and the 
-// AxiStreamPacket and AxiStreamBfm classes.
+// Description: Package for a bi-directional AXI Stream bus functional model
+// (BFM). This consists of the AxiStreamPacket and AxiStreamBfm classes.
+// It's based on the AxiStreamIf in lib/axi4s_svPkgAXI4S.sv
 //
 
 
-
 //-----------------------------------------------------------------------------
-// Unidirectional AXI4-Stream interface
+// AXI-Stream BFM Package
 //-----------------------------------------------------------------------------
 
-interface AxiStreamIf #(
-  parameter int DATA_WIDTH = 64,
-  parameter int USER_WIDTH = 1
-) (
-  input logic clk,
-  input logic rst = 1'b0
-);
-  
-  // Signals that make up a unidirectional AXI-Stream interface
-  logic                    tready;
-  logic                    tvalid;
-  logic [DATA_WIDTH-1:0]   tdata;
-  logic [USER_WIDTH-1:0]   tuser;
-  logic [DATA_WIDTH/8-1:0] tkeep;
-  logic                    tlast;
-
-  // View from the master side
-  modport master (
-    input  clk, rst,
-    output tvalid, tdata, tuser, tkeep, tlast,
-    input  tready
-  );
-
-  // View from the slave side
-  modport slave (
-    input  clk, rst,
-    input  tvalid, tdata, tuser, tkeep, tlast,
-    output tready
-  );
-
-endinterface : AxiStreamIf
+package PkgAxiStreamBfm;
 
+  //---------------------------------------------------------------------------
+  // Raw packets - packet of just bytes
+  //---------------------------------------------------------------------------
 
+  // Ethernet in particular defies normal word boundaries, so underneath treating
+  // it as the most fundamental quantity - Bytes.
+  typedef byte raw_pkt_t[$]; // Byte Queue
+
+  // Push a packet with random data onto to the AXI Stream bus
+  // Args:
+  // - num_bytes: number of random bytes to add to the raw packet.
+  // - pkt: packet with rand data
+  task automatic get_rand_raw_pkt (
+    input int num_bytes,
+    output raw_pkt_t pkt);
+    begin
+      repeat(num_bytes) begin
+        pkt.push_back($urandom);
+      end
+    end
+  endtask
+
+  // Push a packet with a ramp on to the AXI Stream bus
+  // Args:
+  // - num_samps: Packet size in bytes *8
+  // - ramp_start: Start value for the ramp
+  // - ramp_inc: Increment per clock cycle
+  task automatic get_ramp_raw_pkt (
+    input int num_samps,
+    input logic [63:0] ramp_start,
+    input logic [63:0] ramp_inc,
+    input int SWIDTH=64,
+    output raw_pkt_t pkt);
+    begin
+      logic[63:0]       word;
+      automatic integer counter = 0;
+      repeat(num_samps) begin
+        word = ramp_start+(counter*ramp_inc);
+        for (int i=0; i < SWIDTH ; i+=8) begin
+          pkt.push_back(word[i +: 8]);
+        end
+        counter = counter + 1;
+      end
+    end
+  endtask
 
-//-----------------------------------------------------------------------------
-// AXI-Stream BFM Package
-//-----------------------------------------------------------------------------
+  // Comparison Functions
+  function automatic bit raw_pkt_compare(input raw_pkt_t a, input raw_pkt_t b);
 
-package PkgAxiStreamBfm;
+    bit queue_match;
+    queue_match = 1;
+    // check each element of the queue and clear queue_match if they don't match.
+    // workaround for vivado bug - could be a==b
+    foreach(a[i]) queue_match = queue_match && a[i] == b[i];
+    return ((a.size() == b.size()) && queue_match);
 
+  endfunction
 
   //---------------------------------------------------------------------------
   // AXI Stream Packet Class
@@ -73,7 +91,7 @@ package PkgAxiStreamBfm;
 
     typedef AxiStreamPacket #(DATA_WIDTH, USER_WIDTH) AxisPacket_t;
 
-
+    bit verbose=0;
     //------------
     // Properties
     //------------
@@ -105,6 +123,12 @@ package PkgAxiStreamBfm;
       keep = {};
     endfunction;
 
+    // Delete a word from the current packet
+    function void delete(int i);
+      data.delete(i);
+      user.delete(i);
+      keep.delete(i);
+    endfunction;
 
     // Return true if this packet equals that of the argument
     virtual function bit equal(AxisPacket_t packet);
@@ -117,21 +141,30 @@ package PkgAxiStreamBfm;
       foreach (data[i]) begin
         data_a = data[i];
         data_b = packet.data[i];
-        if (data_a !== data_b) return 0;
+        if (data_a !== data_b) begin
+          if (verbose) $display("AxisPacket data mismatch a[%2d]=%X b[%2d]=%X",i,data_a,i,data_b);
+          return 0;
+        end
       end
 
       if (user.size() != packet.user.size()) return 0;
       foreach (data[i]) begin
         user_a = user[i];
         user_b = packet.user[i];
-        if (user_a !== user_b) return 0;
+        if (user_a !== user_b) begin
+          if (verbose) $display("AxisPacket user mismatch a[%2d]=%X b[%2d]=%X",i,user_a,i,user_b);
+          return 0;
+        end
       end
 
       if (keep.size() != packet.keep.size()) return 0;
       foreach (keep[i]) begin
         keep_a = keep[i];
         keep_b = packet.keep[i];
-        if (keep_a !== keep_b) return 0;
+        if (keep_a !== keep_b) begin
+          if (verbose) $display("AxisPacket keep mismatch a[%2d]=%X b[%2d]=%X",i,user_a,i,user_b);
+          return 0;
+        end
       end
 
       return 1;
@@ -141,10 +174,22 @@ package PkgAxiStreamBfm;
     // Format the contents of the packet into a string
     function string sprint();
       string str = "";
+      string data_str = "";
       if (data.size() == user.size() && data.size() == keep.size()) begin
         str = { str, "data, user, keep:\n" };
         foreach (data[i]) begin
-          str = { str, $sformatf("%5d> %X %X %b\n", i, data[i], user[i], keep[i]) };
+          data_str = "";
+          if (DATA_WIDTH > 64) begin
+            for (int b=0; b < DATA_WIDTH; b +=64) begin
+              data_str = { data_str, $sformatf("%3d: %X",b,data[i][b+:64])};
+              if (b+64 < DATA_WIDTH) begin
+                data_str = { data_str, $sformatf("\n       ")};
+              end
+            end
+          end else begin
+            data_str = { data_str, $sformatf("%X",data[i]) };
+          end
+          str = { str, $sformatf("%5d> %s %X %X \n", i, data_str, user[i], keep[i]) };
         end
       end else begin
         str = { str, "data:\n" };
@@ -169,6 +214,45 @@ package PkgAxiStreamBfm;
       $display(sprint());
     endfunction : print
 
+    // Add an array of bytes (little endian)
+    function void push_bytes(raw_pkt_t raw, input user_t user = '0);
+      data_t word;
+      keep_t my_keep;
+      while (raw.size() > 0) begin
+         // fill tkeep
+         // SIZE = TKEEP / 0 = 0000, 1 = 0001, 2 = 0011, etc
+         my_keep = '1;
+         if (raw.size <= DATA_WIDTH/8) begin
+            foreach (my_keep[i]) my_keep[i] = i < (raw.size);
+         end
+         // fill the word with raw data from bottom up
+         word = '0;
+         for (int i = 0; i < DATA_WIDTH/8 ; i++) begin
+            if (my_keep[i]) word[i*8 +: 8] = raw.pop_front();
+         end
+         this.data.push_back(word);
+         this.keep.push_back(my_keep);
+         this.user.push_back(user);
+      end
+    endfunction
+
+    // Dump data contents as an array of bytes. (little endian)
+    function raw_pkt_t dump_bytes();
+      data_t    word;
+      keep_t    my_keep;
+      raw_pkt_t raw;
+      assert (data.size == keep.size) else
+         $fatal("data and keep have different sizes!");
+      foreach (data[i]) begin
+         my_keep = this.keep[i];
+         word    = this.data[i];
+         for (int j = 0; j < DATA_WIDTH/8 ; j++) begin
+            if (my_keep[j]) raw.push_back(word[j*8 +: 8]);
+         end;
+      end
+      return raw;
+    endfunction
+
   endclass : AxiStreamPacket;
 
 
@@ -178,8 +262,13 @@ package PkgAxiStreamBfm;
   //---------------------------------------------------------------------------
 
   class AxiStreamBfm #(
-    parameter int DATA_WIDTH = 64,
-    parameter int USER_WIDTH = 1
+    int DATA_WIDTH = 64,
+    int USER_WIDTH = 1,
+    int MAX_PACKET_BYTES = 0,
+    bit TDATA = 1,
+    bit TUSER = 1,
+    bit TKEEP = 1,
+    bit TLAST = 1
   );
 
     //------------------
@@ -205,13 +294,16 @@ package PkgAxiStreamBfm;
     local const AxisPacket_t::keep_t IDLE_KEEP = {(DATA_WIDTH/8){1'bX}};
 
     // Virtual interfaces for master and slave connections to DUT
-    local virtual AxiStreamIf #(DATA_WIDTH, USER_WIDTH).master master;
-    local virtual AxiStreamIf #(DATA_WIDTH, USER_WIDTH).slave  slave;
+    local virtual AxiStreamIf #(DATA_WIDTH,USER_WIDTH,MAX_PACKET_BYTES,
+                            TDATA,TUSER,TKEEP,TLAST).master master;
+    local virtual AxiStreamIf #(DATA_WIDTH,USER_WIDTH,MAX_PACKET_BYTES,
+                            TDATA,TUSER,TKEEP,TLAST).slave  slave;
     // NOTE: We should not need these flags if Vivado would be OK with null check
     //       without throwing unnecessary null-ptr deref exceptions.
     local bit master_en;
     local bit slave_en;
 
+    bit slave_tready_init = 0;
     // Queues to store the bus transactions
     mailbox #(AxisPacket_t) tx_packets;
     mailbox #(AxisPacket_t) rx_packets;
@@ -220,6 +312,8 @@ package PkgAxiStreamBfm;
     protected int master_stall_prob = DEF_STALL_PROB;
     protected int slave_stall_prob  = DEF_STALL_PROB;
 
+    // Number of clocks betwen packets
+    int inter_packet_gap = 0;
 
     //---------
     // Methods
@@ -231,11 +325,13 @@ package PkgAxiStreamBfm;
     endfunction : packets_equal
 
 
-    // Class constructor. This must be given an interface for the master 
+    // Class constructor. This must be given an interface for the master
     // connection and an interface for the slave connection.
     function new(
-      virtual AxiStreamIf #(DATA_WIDTH, USER_WIDTH).master master,
-      virtual AxiStreamIf #(DATA_WIDTH, USER_WIDTH).slave  slave
+      virtual AxiStreamIf #(DATA_WIDTH,USER_WIDTH,MAX_PACKET_BYTES,
+                            TDATA,TUSER,TKEEP,TLAST).master master,
+      virtual AxiStreamIf #(DATA_WIDTH,USER_WIDTH,MAX_PACKET_BYTES,
+                            TDATA,TUSER,TKEEP,TLAST).slave  slave
     );
       this.master_en = (master != null);
       this.slave_en = (slave != null);
@@ -253,7 +349,7 @@ package PkgAxiStreamBfm;
     endtask : put
 
 
-    // Attempt to queue the provided packet for transmission. Return 1 if 
+    // Attempt to queue the provided packet for transmission. Return 1 if
     // successful, return 0 if the queue is full.
     function bit try_put(AxisPacket_t packet);
       assert (master_en) else $fatal(1, "Cannot use TX operations for a null master");
@@ -268,7 +364,7 @@ package PkgAxiStreamBfm;
     endtask : get
 
 
-    // Get the next packet if there's one available and return 1. Return 0 if 
+    // Get the next packet if there's one available and return 1. Return 0 if
     // there's no packet available.
     function bit try_get(output AxisPacket_t packet);
       assert (slave_en) else $fatal(1, "Cannot use RX operations for a null slave");
@@ -276,7 +372,7 @@ package PkgAxiStreamBfm;
     endfunction : try_get
 
 
-    // Get the next packet when it becomes available (wait if necessary), but 
+    // Get the next packet when it becomes available (wait if necessary), but
     // don't remove it from the receive queue.
     task peek(output AxisPacket_t packet);
       assert (slave_en) else $fatal(1, "Cannot use RX operations for a null slave");
@@ -284,8 +380,8 @@ package PkgAxiStreamBfm;
     endtask : peek
 
 
-    // Get the next packet if there's one available and return 1, but don't 
-    // remove it from the receive queue. Return 0 if there's no packet 
+    // Get the next packet if there's one available and return 1, but don't
+    // remove it from the receive queue. Return 0 if there's no packet
     // available.
     function bit try_peek(output AxisPacket_t packet);
       assert (slave_en) else $fatal(1, "Cannot use RX operations for a null slave");
@@ -300,8 +396,8 @@ package PkgAxiStreamBfm;
     endfunction
 
 
-    // Wait until num packets have started transmission (i.e., until num 
-    // packets have been dequeued). Set num = -1 to wait until all currently 
+    // Wait until num packets have started transmission (i.e., until num
+    // packets have been dequeued). Set num = -1 to wait until all currently
     // queued packets have started transmission.
     task wait_send(int num = -1);
       int end_num;
@@ -318,7 +414,7 @@ package PkgAxiStreamBfm;
     endtask : wait_send
 
 
-    // Wait until num packets have completed transmission. Set num = -1 to wait 
+    // Wait until num packets have completed transmission. Set num = -1 to wait
     // for all currently queued packets to complete transmission.
     task wait_complete(int num = -1);
       int end_num;
@@ -340,7 +436,7 @@ package PkgAxiStreamBfm;
     endtask : wait_complete
 
 
-    // Set the probability (as a percentage, 0 to 100) of the master interface 
+    // Set the probability (as a percentage, 0 to 100) of the master interface
     // stalling due to lack of data to send.
     function void set_master_stall_prob(int stall_probability = DEF_STALL_PROB);
       assert(stall_probability >= 0 && stall_probability <= 100) else begin
@@ -350,7 +446,7 @@ package PkgAxiStreamBfm;
     endfunction
 
 
-    // Set the probability (as a percentage, 0 to 100) of the slave interface 
+    // Set the probability (as a percentage, 0 to 100) of the slave interface
     // stalling due to lack of buffer space.
     function void set_slave_stall_prob(int stall_probability = DEF_STALL_PROB);
       assert(stall_probability >= 0 && stall_probability <= 100) else begin
@@ -360,14 +456,14 @@ package PkgAxiStreamBfm;
     endfunction
 
 
-    // Get the probability (as a percentage, 0 to 100) of the master interface 
+    // Get the probability (as a percentage, 0 to 100) of the master interface
     // stalling due to lack of data to send.
     function int get_master_stall_prob(int stall_probability = DEF_STALL_PROB);
       return master_stall_prob;
     endfunction
 
 
-    // Get the probability (as a percentage, 0 to 100) of the slave interface 
+    // Get the probability (as a percentage, 0 to 100) of the slave interface
     // stalling due to lack of buffer space.
     function int get_slave_stall_prob(int stall_probability = DEF_STALL_PROB);
       return slave_stall_prob;
@@ -397,8 +493,10 @@ package PkgAxiStreamBfm;
       master.tlast  <= 0;
 
       forever begin
-        @(posedge master.clk);
-        if (master.rst) continue;
+        repeat(inter_packet_gap) begin
+          @(posedge master.clk);
+          if (master.rst) continue;
+        end
 
         if (tx_packets.try_get(packet)) begin
           foreach (packet.data[i]) begin
@@ -433,6 +531,9 @@ package PkgAxiStreamBfm;
           master.tuser  <= IDLE_USER;
           master.tkeep  <= IDLE_KEEP;
           master.tlast  <= 0;
+        end else begin
+          @(posedge master.clk);
+          if (master.rst) continue;
         end
       end
     endtask : master_body
@@ -445,7 +546,7 @@ package PkgAxiStreamBfm;
     local task slave_body();
       AxisPacket_t packet = new();
 
-      slave.tready <= 0;
+      slave.tready <= slave_tready_init;
 
       forever begin
         @(posedge slave.clk);