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module time_receiver
(input clk, input rst,
output reg [63:0] vita_time,
output sync_rcvd,
input exp_time_in);
wire code_err, disp_err, dispout, complete_word;
reg disp_reg;
reg [9:0] shiftreg;
reg [3:0] bit_count;
wire [8:0] dataout;
reg [8:0] dataout_reg;
always @(posedge clk)
shiftreg <= {exp_time_in, shiftreg[9:1]};
localparam COMMA_0 = 10'h283;
localparam COMMA_1 = 10'h17c;
wire found_comma = (shiftreg == COMMA_0) | (shiftreg == COMMA_1);
wire set_disp = (shiftreg == COMMA_1);
always @(posedge clk)
if(rst)
bit_count <= 0;
else if(found_comma | complete_word)
bit_count <= 0;
else
bit_count <= bit_count + 1;
assign complete_word = (bit_count == 9);
always @(posedge clk)
if(set_disp)
disp_reg <= 1;
else if(complete_word)
disp_reg <= dispout;
always @(posedge clk)
if(complete_word)
dataout_reg <= dataout;
decode_8b10b decode_8b10b
(.datain(shiftreg),.dispin(disp_reg),
.dataout(dataout),.dispout(dispout),
.code_err(code_err),.disp_err(disp_err) );
reg error;
always @(posedge clk)
if(complete_word)
error <= code_err | disp_err;
localparam STATE_IDLE = 0;
localparam STATE_T0 = 1;
localparam STATE_T1 = 2;
localparam STATE_T2 = 3;
localparam STATE_T3 = 4;
localparam STATE_T4 = 5;
localparam STATE_T5 = 6;
localparam STATE_T6 = 7;
localparam STATE_T7 = 8;
localparam STATE_TAIL = 9;
localparam HEAD = 9'h13c;
localparam TAIL = 9'h1F7;
reg [3:0] state;
always @(posedge clk)
if(rst)
state <= STATE_IDLE;
else if(complete_word)
if(code_err | disp_err)
state <= STATE_IDLE;
else
case(state)
STATE_IDLE :
if(dataout_reg == HEAD)
state <= STATE_T0;
STATE_T0 :
begin
vita_time[63:56] <= dataout_reg[7:0];
state <= STATE_T1;
end
STATE_T1 :
begin
vita_time[55:48] <= dataout_reg[7:0];
state <= STATE_T2;
end
STATE_T2 :
begin
vita_time[47:40] <= dataout_reg[7:0];
state <= STATE_T3;
end
STATE_T3 :
begin
vita_time[39:32] <= dataout_reg[7:0];
state <= STATE_T4;
end
STATE_T4 :
begin
vita_time[31:24] <= dataout_reg[7:0];
state <= STATE_T5;
end
STATE_T5 :
begin
vita_time[23:16] <= dataout_reg[7:0];
state <= STATE_T6;
end
STATE_T6 :
begin
vita_time[15:8] <= dataout_reg[7:0];
state <= STATE_T7;
end
STATE_T7 :
begin
vita_time[7:0] <= dataout_reg[7:0];
state <= STATE_TAIL;
end
STATE_TAIL :
state <= STATE_IDLE;
endcase // case(state)
assign sync_rcvd = (complete_word & (state == STATE_TAIL) & (dataout_reg[8:0] == TAIL));
endmodule // time_sender
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