| Line 11... |
Line 11... |
// finely tracked clock speed output, to allow for fine clock precision
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// finely tracked clock speed output, to allow for fine clock precision
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// and good freewheeling even if/when GPS is lost.
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// and good freewheeling even if/when GPS is lost.
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//
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//
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//
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//
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// Creator: Dan Gisselquist, Ph.D.
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// Creator: Dan Gisselquist, Ph.D.
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// Gisselquist Tecnology, LLC
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// Gisselquist Technology, LLC
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//
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//
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///////////////////////////////////////////////////////////////////////////
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///////////////////////////////////////////////////////////////////////////
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//
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//
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// Copyright (C) 2015, Gisselquist Technology, LLC
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// Copyright (C) 2015, Gisselquist Technology, LLC
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//
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//
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| Line 50... |
Line 50... |
// Output controls
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// Output controls
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o_sseg, o_led, o_interrupt,
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o_sseg, o_led, o_interrupt,
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// A once-per-day strobe on the last clock of the day
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// A once-per-day strobe on the last clock of the day
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o_ppd,
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o_ppd,
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// GPS interface
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// GPS interface
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i_gps_valid, i_gps_pps, i_gps_ckspeed);
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i_gps_valid, i_gps_pps, i_gps_ckspeed,
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// Our personal timing, for debug purposes
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o_rtc_pps);
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parameter DEFAULT_SPEED = 32'd2814750; //2af31e = 2^48 / 100e6 MHz
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parameter DEFAULT_SPEED = 32'd2814750; //2af31e = 2^48 / 100e6 MHz
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input i_clk;
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input i_clk;
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input i_wb_cyc, i_wb_stb, i_wb_we;
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input i_wb_cyc, i_wb_stb, i_wb_we;
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input [1:0] i_wb_addr;
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input [1:0] i_wb_addr;
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input [31:0] i_wb_data;
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input [31:0] i_wb_data;
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| Line 64... |
Line 66... |
output wire [15:0] o_led;
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output wire [15:0] o_led;
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output wire o_interrupt, o_ppd;
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output wire o_interrupt, o_ppd;
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// GPS interface
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// GPS interface
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input i_gps_valid, i_gps_pps;
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input i_gps_valid, i_gps_pps;
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input [31:0] i_gps_ckspeed;
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input [31:0] i_gps_ckspeed;
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// Personal PPS
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output wire o_rtc_pps;
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reg [23:0] clock;
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reg [23:0] clock;
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reg [31:0] stopwatch, ckspeed;
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reg [31:0] stopwatch, ckspeed;
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reg [25:0] timer;
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reg [25:0] timer;
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| Line 78... |
Line 82... |
assign al_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr==2'b11));
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assign al_sel = ((i_wb_cyc)&&(i_wb_stb)&&(i_wb_addr==2'b11));
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reg [39:0] ck_counter;
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reg [39:0] ck_counter;
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reg ck_carry;
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reg ck_carry;
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always @(posedge i_clk)
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always @(posedge i_clk)
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if ((i_gps_valid)&&(i_gps_pps))
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begin
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ck_carry <= 0;
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// Start our counter 2 clocks into the future.
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// Why? Because if we hit the PPS, we'll be delayed
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// one clock from true time. This (hopefully) locks
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// us back onto true time. Further, if we end up
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// off (i.e., go off before the GPS tick ...) then
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// the GPS tick will put us back on track ... likewise
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// we've got code following that should keep us from
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// ever producing two PPS's per second.
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ck_counter <= { 7'h00, ckspeed, 1'b0 };
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end else
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{ ck_carry, ck_counter } <= ck_counter + { 8'h00, ckspeed };
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{ ck_carry, ck_counter } <= ck_counter + { 8'h00, ckspeed };
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wire ck_pps;
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reg ck_pps;
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reg ck_prepps, ck_ppm, ck_pph, ck_ppd;
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reg ck_ppm, ck_pph, ck_ppd;
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reg [7:0] ck_sub;
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reg [7:0] ck_sub;
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initial clock = 24'h00000000;
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initial clock = 24'h00000000;
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assign ck_pps = (ck_carry)&&(ck_prepps);
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always @(posedge i_clk)
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if ((i_gps_pps)&&(i_gps_valid)&&(ck_sub[7]))
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ck_pps <= 1'b1;
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else if ((ck_carry)&&(ck_sub == 8'hff))
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ck_pps <= 1'b1;
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else
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ck_pps <= 1'b0;
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assign o_rtc_pps = ck_pps;
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always @(posedge i_clk)
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always @(posedge i_clk)
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begin
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begin
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if ((i_gps_valid)&&(i_gps_pps))
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if ((i_gps_valid)&&(i_gps_pps))
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ck_sub <= 0;
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ck_sub <= 0;
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else if (ck_carry)
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else if (ck_carry)
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ck_sub <= ck_sub + 1;
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ck_sub <= ck_sub + 1;
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if (i_gps_valid)
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ck_prepps <= i_gps_pps;
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else
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ck_prepps <= (ck_sub == 8'hff);
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if (ck_pps)
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if (ck_pps)
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begin // advance the seconds
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begin // advance the seconds
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if (clock[3:0] >= 4'h9)
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if (clock[3:0] >= 4'h9)
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clock[3:0] <= 4'h0;
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clock[3:0] <= 4'h0;
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| Line 425... |
Line 446... |
dmask[3] <= (2'b00 != clock[21:20]);
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dmask[3] <= (2'b00 != clock[21:20]);
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end
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end
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endcase
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endcase
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wire [31:0] w_sseg;
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wire [31:0] w_sseg;
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assign w_sseg[ 0] = (~ck_sub[7]);
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assign w_sseg[ 0] = (i_gps_valid)?(ck_sub[7:5]==3'h0):(~ck_sub[0]);
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assign w_sseg[ 8] = (~ck_sub[6])&&(~ck_sub[7]);
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assign w_sseg[ 8] = (i_gps_valid)?(ck_sub[7:5]==3'h0):(~ck_sub[0]);
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assign w_sseg[16] = (~ck_sub[5])&&(~ck_sub[6])&&(~ck_sub[7]);
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assign w_sseg[16] = (i_gps_valid)?(ck_sub[7:5]==3'h0):(~ck_sub[0]);
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// assign w_sseg[ 8] = w_sseg[0];
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// assign w_sseg[16] = w_sseg[0];
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assign w_sseg[24] = 1'b0;
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assign w_sseg[24] = 1'b0;
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hexmap ha(i_clk, h_sseg[ 3: 0], w_sseg[ 7: 1]);
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hexmap ha(i_clk, h_sseg[ 3: 0], w_sseg[ 7: 1]);
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hexmap hb(i_clk, h_sseg[ 7: 4], w_sseg[15: 9]);
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hexmap hb(i_clk, h_sseg[ 7: 4], w_sseg[15: 9]);
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hexmap hc(i_clk, h_sseg[11: 8], w_sseg[23:17]);
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hexmap hc(i_clk, h_sseg[11: 8], w_sseg[23:17]);
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hexmap hd(i_clk, h_sseg[15:12], w_sseg[31:25]);
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hexmap hd(i_clk, h_sseg[15:12], w_sseg[31:25]);
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