Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus.

1 files changed, 90 insertions, 0 deletions

diff --git a/fpga/usrp3/lib/packet_proc/cvita_dechunker.v b/fpga/usrp3/lib/packet_proc/cvita_dechunker.v
new file mode 100644
index 000000000..2ad873305
--- /dev/null
+++ b/fpga/usrp3/lib/packet_proc/cvita_dechunker.v
@@ -0,0 +1,90 @@
+//
+// Copyright 2013 Ettus Research LLC
+//
+
+
+module cvita_dechunker # (
+   parameter PAD_VALUE = 64'hFFFFFFFF_FFFFFFFF
+) (
+   input          clk,
+   input          reset,
+   input          clear,
+   input [15:0]   frame_size,
+
+   input [63:0]   i_tdata,
+   input          i_tvalid,
+   output         i_tready,
+   
+   output [63:0]  o_tdata,
+   output         o_tlast,
+   output         o_tvalid,
+   input          o_tready,
+
+   output         error
+);
+
+   localparam ST_HEADER  = 2'd0;
+   localparam ST_DATA    = 2'd1;
+   localparam ST_PADDING = 2'd2;
+   localparam ST_ERROR   = 2'd3;
+
+   reg [1:0]   state;
+   reg [15:0]  frame_rem, pkt_rem;
+   wire        i_tlast;
+
+   wire [15:0] cvita_len_ceil = i_tdata[47:32] + 7;
+   wire [15:0] axi_len = {3'b000, cvita_len_ceil[15:3]};
+
+   always @(posedge clk) begin
+      if (reset | clear) begin
+         state <= ST_HEADER;
+         frame_rem <= 16'd0;
+         pkt_rem   <= 16'd0;
+      end else if (i_tvalid & i_tready) begin
+         case (state)
+            ST_HEADER: begin
+               if (axi_len > frame_size)
+                  state <= ST_ERROR;
+               else if (~o_tlast)
+                  state <= ST_DATA;
+               else
+                  state <= ST_PADDING;
+                  
+               frame_rem <= frame_size - 16'd1;
+               pkt_rem   <= axi_len - 16'd1;
+            end
+         
+            ST_DATA: begin
+               if (o_tlast) begin
+                  state   <= i_tlast ? ST_HEADER : ST_PADDING;
+                  pkt_rem <= 16'd0;
+               end else begin
+                  state   <= ST_DATA;
+                  pkt_rem <= pkt_rem - 16'd1;
+               end
+               frame_rem <= frame_rem - 16'd1;
+            end
+
+            ST_PADDING: begin
+               if (i_tlast) begin
+                  state   <= ST_HEADER;
+                  frame_rem <= 16'd0;
+               end else begin
+                  state   <= ST_PADDING;
+                  frame_rem <= frame_rem - 16'd1;
+               end
+            end
+         endcase   
+      end   
+   end
+   
+   assign i_tready = o_tready | (state == ST_PADDING);
+   assign i_tlast = (frame_rem == 16'd1); //Temp signal
+   
+   assign o_tvalid = i_tvalid & (state != ST_PADDING);
+   assign o_tlast = (pkt_rem != 0) ? (pkt_rem == 16'd1) : (axi_len == 16'd1);
+   assign o_tdata  = i_tdata;
+   
+   assign error = (state == ST_ERROR);
+
+endmodule // cvita_dechunker