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-rw-r--r--usrp2/timing/time_sender.v110
1 files changed, 110 insertions, 0 deletions
diff --git a/usrp2/timing/time_sender.v b/usrp2/timing/time_sender.v
new file mode 100644
index 000000000..aa2fcbbdb
--- /dev/null
+++ b/usrp2/timing/time_sender.v
@@ -0,0 +1,110 @@
+
+
+module time_sender
+ (input clk, input rst,
+ input [31:0] master_time,
+ input send_sync,
+ output exp_pps_out);
+
+ reg [7:0] datain;
+ reg k;
+ wire [9:0] dataout;
+ reg [9:0] dataout_reg;
+ reg disp_reg;
+ wire disp, new_word;
+
+ encode_8b10b encode_8b10b
+ (.datain({k,datain}),.dispin(disp_reg),
+ .dataout(dataout),.dispout(disp));
+
+ assign exp_pps_out = dataout_reg[0];
+
+ always @(posedge clk)
+ if(rst)
+ disp_reg <= 0;
+ else if(new_word)
+ disp_reg <= disp;
+
+ always @(posedge clk)
+ if(rst)
+ dataout_reg <= 0;
+ else if(new_word)
+ dataout_reg <= dataout;
+ else
+ dataout_reg <= {1'b0,dataout_reg[9:1]};
+
+ reg [4:0] state;
+ reg [3:0] bit_count;
+
+ assign new_word = (bit_count == 9);
+
+ always @(posedge clk)
+ if(rst)
+ bit_count <= 0;
+ else if(new_word | send_sync)
+ bit_count <= 0;
+ else
+ bit_count <= bit_count + 1;
+
+ localparam SEND_IDLE = 0;
+ localparam SEND_HEAD = 1;
+ localparam SEND_T0 = 2;
+ localparam SEND_T1 = 3;
+ localparam SEND_T2 = 4;
+ localparam SEND_T3 = 5;
+
+ localparam COMMA = 8'hBC;
+ localparam HEAD = 8'h3C;
+
+ reg [31:0] master_time_reg;
+
+ always @(posedge clk)
+ if(rst)
+ master_time_reg <= 0;
+ else if(send_sync)
+ master_time_reg <= master_time;
+
+ always @(posedge clk)
+ if(rst)
+ begin
+ {k,datain} <= 0;
+ state <= SEND_IDLE;
+ end
+ else
+ if(send_sync)
+ state <= SEND_HEAD;
+ else if(new_word)
+ case(state)
+ SEND_IDLE :
+ {k,datain} <= {1'b1,COMMA};
+ SEND_HEAD :
+ begin
+ {k,datain} <= {1'b1, HEAD};
+ state <= SEND_T0;
+ end
+ SEND_T0 :
+ begin
+ {k,datain} <= {1'b0, master_time_reg[31:24] };
+ state <= SEND_T1;
+ end
+ SEND_T1 :
+ begin
+ {k,datain} <= {1'b0, master_time_reg[23:16]};
+ state <= SEND_T2;
+ end
+ SEND_T2 :
+ begin
+ {k,datain} <= {1'b0, master_time_reg[15:8]};
+ state <= SEND_T3;
+ end
+ SEND_T3 :
+ begin
+ {k,datain} <= {1'b0, master_time_reg[7:0]};
+ state <= SEND_IDLE;
+ end
+ default :
+ state <= SEND_IDLE;
+ endcase // case(state)
+
+
+endmodule // time_sender