Merged features/inband-usb r5224:6306 into trunk.

This is work-in-progress on inband signaling for the USRP1.


git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@6307 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 132 insertions, 0 deletions

diff --git a/usrp/fpga/inband_lib/packet_builder.v b/usrp/fpga/inband_lib/packet_builder.v
new file mode 100755
index 000000000..205293479
--- /dev/null
+++ b/usrp/fpga/inband_lib/packet_builder.v
@@ -0,0 +1,132 @@
+module packet_builder #(parameter NUM_CHAN = 1)(
+    // System
+    input rxclk,
+    input reset,
+	 input [31:0] adctime,
+	 input [3:0] channels,
+    // ADC side
+    input [15:0]chan_fifodata,
+    input [NUM_CHAN:0]chan_empty,
+    input [9:0]chan_usedw,
+    output reg [3:0]rd_select,
+    output reg chan_rdreq,
+    // FX2 side
+    output reg WR,
+    output reg [15:0]fifodata,
+    input have_space, 
+	input wire [31:0]rssi_0, input wire [31:0]rssi_1, input wire [31:0]rssi_2,
+	input wire [31:0]rssi_3, output wire [7:0] debugbus);
+    
+    
+    // States
+    `define IDLE                     3'd0
+    `define HEADER1                  3'd1
+	`define HEADER2					 3'd2
+    `define TIMESTAMP                3'd3
+ 	`define FORWARD					 3'd4
+	
+    `define MAXPAYLOAD 504
+    
+    `define PAYLOAD_LEN 8:0
+    `define TAG 12:9
+    `define MBZ 15:13
+    
+    `define CHAN 4:0
+    `define RSSI 10:5
+    `define BURST 12:11
+    `define DROPPED 13
+    `define UNDERRUN 14
+    `define OVERRUN 15
+    
+    reg [2:0] state;
+    reg [8:0] read_length;
+    reg [8:0] payload_len;
+    reg tstamp_complete;
+    reg [3:0] check_next;
+	wire [8:0] chan_used;
+    wire [31:0] true_rssi;
+
+	assign debugbus = {state, chan_empty[0], chan_empty[1], check_next[0],
+						have_space, rd_select[0]};
+	assign chan_used = chan_usedw[8:0];
+	assign true_rssi = (rd_select[1]) ? ((rd_select[0]) ? rssi_3:rssi_2) :
+							((rd_select[0]) ? rssi_1:rssi_0);	
+    always @(posedge rxclk)
+    begin
+        if (reset)
+          begin
+            WR <= 0;
+            rd_select <= 0;
+            chan_rdreq <= 0;
+            tstamp_complete <= 0;
+            check_next <= 0;
+            state <= `IDLE;
+          end
+        else case (state)
+            `IDLE: begin
+				if (have_space)
+				  begin
+					if(~chan_empty[check_next])
+				      begin
+                		state <= #1 `HEADER1;
+						rd_select <= #1 check_next;
+				  	  end
+					check_next <= #1 (check_next == channels ? 4'd0 : check_next + 4'd1);
+				  end	
+            end
+            
+            `HEADER1: begin
+                fifodata[`PAYLOAD_LEN] <= #1 (chan_used > 9'd252
+                                           ? 9'd252 : chan_used << 1);
+                payload_len <= #1 (chan_used > 9'd252
+                                ? 9'd252 : chan_used << 1);
+                fifodata[`TAG] <= #1 0;
+                fifodata[`MBZ] <= #1 0;
+                WR <= #1 1;
+                
+                state <= #1 `HEADER2;
+                read_length <= #1 0;
+            end
+            
+            `HEADER2: begin
+                fifodata[`CHAN] <= #1 (check_next == 4'd0 ? 5'h1f : {1'd0, check_next - 4'd1});
+                fifodata[`RSSI] <= #1 true_rssi[5:0];
+                fifodata[`BURST] <= #1 0;
+                fifodata[`DROPPED] <= #1 0;
+                fifodata[`UNDERRUN] <= #1 0;
+                fifodata[`OVERRUN] <= #1 0;
+                
+                state <= #1 `TIMESTAMP;
+            end
+            
+            `TIMESTAMP: begin
+                fifodata <= #1 (tstamp_complete ? adctime[31:16] : adctime[15:0]);
+                tstamp_complete <= #1 ~tstamp_complete;
+                
+                if (~tstamp_complete)
+                    chan_rdreq <= #1 1;
+                
+                state <= #1 (tstamp_complete ? `FORWARD : `TIMESTAMP);
+            end
+            
+            `FORWARD: begin
+                read_length <= #1 read_length + 9'd2;
+                fifodata <= #1 (read_length >= payload_len ? 16'hDEAD : chan_fifodata);
+                
+                if (read_length >= `MAXPAYLOAD)
+                  begin
+                    WR <= #1 0;
+                    state <= #1 `IDLE;
+                  end
+                else if (read_length == payload_len - 4)
+                    chan_rdreq <= #1 0;
+            end
+            
+            default: begin
+				//handling error state
+                state <= `IDLE;
+            end
+            endcase
+    end
+endmodule
+