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[/] [uart6551/] [trunk/] [trunk/] [rtl/] [uart6551BaudLUT.sv] - Blame information for rev 13

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// ============================================================================
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//        __
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//   \\__/ o\    (C) 2005-2023  Robert Finch, Waterloo
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//    \  __ /    All rights reserved.
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//     \/_//     robfinch@finitron.ca
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//       ||
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//
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//
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// BSD 3-Clause License
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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//
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// 1. Redistributions of source code must retain the above copyright notice, this
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//    list of conditions and the following disclaimer.
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//
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// 2. Redistributions in binary form must reproduce the above copyright notice,
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//    this list of conditions and the following disclaimer in the documentation
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//    and/or other materials provided with the distribution.
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//
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// 3. Neither the name of the copyright holder nor the names of its
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//    contributors may be used to endorse or promote products derived from
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//    this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// ============================================================================
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//
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module uart6551BaudLUT(a, o);
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parameter pClkFreq = 100;
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parameter pCounterBits = 24;
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input [4:0] a;
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output reg [pCounterBits-1:0] o;
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// table for a 50.000MHz reference clock
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// value = 50,000,000 / (baud * 16)
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always_comb
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case(pClkFreq)
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20:
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= 24'd25000; // 50 baud
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        5'd2:   o <= 24'd16667; // 75 baud
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        5'd3:   o <= 24'd11372; // 109.92 baud
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        5'd4:   o <= 24'd9270;  // 134.58 baud
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        5'd5:   o <= 24'd8333;  // 150 baud
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        5'd6:   o <= 24'd4167;  // 300 baud
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        5'd7:   o <= 24'd2083;  // 600 baud
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        5'd8:   o <= 24'd1042;  // 1200 baud
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        5'd9:   o <= 24'd694;   // 1800 baud
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        5'd10:  o <= 24'd521;   // 2400 baud
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        5'd11:  o <= 24'd347;   // 3600 baud
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        5'd12:  o <= 24'd260;   // 4800 baud
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        5'd13:  o <= 24'd174;   // 7200 baud
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        5'd14:  o <= 24'd130;   // 9600 baud
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        5'd15:  o <= 24'd65;    // 19200 baud
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        5'd16:  o <= 24'd33;    // 38400 baud
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        5'd17:  o <= 24'd22;    // 57600 baud
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        5'd18:  o <= 24'd11;    // 115200 baud
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        5'd19:  o <= 24'd5;     // 230400 baud
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        5'd20:  o <= 24'd3;     // 460800 baud
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        5'd21:  o <= 24'd1;     // 921600 baud
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        default:        o <= 24'd130;   // 9600 baud
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        endcase
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40:
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= 24'd50000; // 50 baud
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        5'd2:   o <= 24'd33333; // 75 baud
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        5'd3:   o <= 24'd22744; // 109.92 baud
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        5'd4:   o <= 24'd18576; // 134.58 baud
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        5'd5:   o <= 24'd16667; // 150 baud
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        5'd6:   o <= 24'd8333;  // 300 baud
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        5'd7:   o <= 24'd4167;  // 600 baud
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        5'd8:   o <= 24'd2083;  // 1200 baud
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        5'd9:   o <= 24'd1389;  // 1800 baud
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        5'd10:  o <= 24'd1042;  // 2400 baud
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        5'd11:  o <= 24'd694;   // 3600 baud
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        5'd12:  o <= 24'd521;   // 4800 baud
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        5'd13:  o <= 24'd347;   // 7200 baud
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        5'd14:  o <= 24'd260;   // 9600 baud
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        5'd15:  o <= 24'd130;   // 19200 baud
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        5'd16:  o <= 24'd65;    // 38400 baud
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        5'd17:  o <= 24'd43;    // 57600 baud
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        5'd18:  o <= 24'd22;    // 115200 baud
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        5'd19:  o <= 24'd11;    // 230400 baud
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        5'd20:  o <= 24'd5;     // 460800 baud
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        5'd21:  o <= 24'd3;     // 921600 baud
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        default:        o <= 24'd260;   // 9600 baud
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        endcase
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50:
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= 24'd62500; // 50 baud
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        5'd2:   o <= 24'd41667; // 75 baud
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        5'd3:   o <= 24'd28617; // 109.92 baud
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        5'd4:   o <= 24'd23220; // 134.58 baud
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        5'd5:   o <= 24'd20833; // 150 baud
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        5'd6:   o <= 24'd10417; // 300 baud
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        5'd7:   o <= 24'd5208;  // 600 baud
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        5'd8:   o <= 24'd2604;  // 1200 baud
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        5'd9:   o <= 24'd1736;  // 1800 baud
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        5'd10:  o <= 24'd1302;  // 2400 baud
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        5'd11:  o <= 24'd868;   // 3600 baud
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        5'd12:  o <= 24'd651;   // 4800 baud
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        5'd13:  o <= 24'd434;   // 7200 baud
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        5'd14:  o <= 24'd326;   // 9600 baud
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        5'd15:  o <= 24'd163;   // 19200 baud
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        5'd16:  o <= 24'd81;    // 38400 baud
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        5'd17:  o <= 24'd54;    // 57600 baud
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        5'd18:  o <= 24'd27;    // 115200 baud
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        5'd19:  o <= 24'd14;    // 230400 baud
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        5'd20:  o <= 24'd7;     // 460800 baud
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        5'd21:  o <= 24'd3;     // 921600 baud
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        default:        o <= 24'd326;   // 9600 baud
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        endcase
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80:
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= 24'd100000;        // 50 baud
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        5'd2:   o <= 24'd66667; // 75 baud
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        5'd3:   o <= 24'd45488; // 109.92 baud
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        5'd4:   o <= 24'd37153; // 134.58 baud
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        5'd5:   o <= 24'd33333; // 150 baud
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        5'd6:   o <= 24'd16667; // 300 baud
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        5'd7:   o <= 24'd8333;  // 600 baud
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        5'd8:   o <= 24'd4167;  // 1200 baud
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        5'd9:   o <= 24'd2778;  // 1800 baud
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        5'd10:  o <= 24'd2083;  // 2400 baud
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        5'd11:  o <= 24'd1389;  // 3600 baud
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        5'd12:  o <= 24'd1042;  // 4800 baud
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        5'd13:  o <= 24'd694;   // 7200 baud
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        5'd14:  o <= 24'd521;   // 9600 baud
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        5'd15:  o <= 24'd260;   // 19200 baud
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        5'd16:  o <= 24'd130;   // 38400 baud
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        5'd17:  o <= 24'd87;    // 57600 baud
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        5'd18:  o <= 24'd43;    // 115200 baud
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        5'd19:  o <= 24'd22;    // 230400 baud
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        5'd20:  o <= 24'd11;    // 460800 baud
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        5'd21:  o <= 24'd5;     // 921600 baud
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        default:        o <= 24'd521;   // 9600 baud
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        endcase
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= 24'd125000;        // 50 baud
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        5'd2:   o <= 24'd83333; // 75 baud
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        5'd3:   o <= 24'd56860; // 109.92 baud
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        5'd4:   o <= 24'd46441; // 134.58 baud
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        5'd5:   o <= 24'd41667; // 150 baud
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        5'd6:   o <= 24'd20833; // 300 baud
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        5'd7:   o <= 24'd10417; // 600 baud
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        5'd8:   o <= 24'd5208;  // 1200 baud
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        5'd9:   o <= 24'd3472;  // 1800 baud
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        5'd10:  o <= 24'd2604;  // 2400 baud
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        5'd11:  o <= 24'd1736;  // 3600 baud
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        5'd12:  o <= 24'd1302;  // 4800 baud
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        5'd13:  o <= 24'd868;   // 7200 baud
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        5'd14:  o <= 24'd651;   // 9600 baud
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        5'd15:  o <= 24'd326;   // 19200 baud
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        5'd16:  o <= 24'd163;   // 38400 baud
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        5'd17:  o <= 24'd109;   // 57600 baud
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        5'd18:  o <= 24'd54;    // 115200 baud
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        5'd19:  o <= 24'd27;    // 230400 baud
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        5'd20:  o <= 24'd14;    // 460800 baud
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        5'd21:  o <= 24'd7;     // 921600 baud
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        default:        o <= 24'd651;   // 9600 baud
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        endcase
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default:
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        case (a)        // synopsys full_case parallel_case
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        5'd0:   o <= 0;
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        5'd1:   o <= (pClkFreq*1e6)/(16*50);    // 50 baud
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        5'd2:   o <= (pClkFreq*1e6)/(16*75);    // 75 baud
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        5'd3:   o <= (pClkFreq*1e6)/(16*109.92);        // 109.92 baud
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        5'd4:   o <= (pClkFreq*1e6)/(16*134.58);        // 134.58 baud
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        5'd5:   o <= (pClkFreq*1e6)/(16*150);   // 150 baud
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        5'd6:   o <= (pClkFreq*1e6)/(16*300);   // 300 baud
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        5'd7:   o <= (pClkFreq*1e6)/(16*600);   // 600 baud
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        5'd8:   o <= (pClkFreq*1e6)/(16*1200);  // 1200 baud
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        5'd9:   o <= (pClkFreq*1e6)/(16*1800);  // 1800 baud
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        5'd10:  o <= (pClkFreq*1e6)/(16*2400);  // 2400 baud
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        5'd11:  o <= (pClkFreq*1e6)/(16*3600);  // 3600 baud
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        5'd12:  o <= (pClkFreq*1e6)/(16*4800);  // 4800 baud
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        5'd13:  o <= (pClkFreq*1e6)/(16*7200);  // 7200 baud
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        5'd14:  o <= (pClkFreq*1e6)/(16*9600);  // 9600 baud
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        5'd15:  o <= (pClkFreq*1e6)/(16*19200); // 19200 baud
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        5'd16:  o <= (pClkFreq*1e6)/(16*38400); // 38400 baud
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        5'd17:  o <= (pClkFreq*1e6)/(16*57600); // 57600 baud
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        5'd18:  o <= (pClkFreq*1e6)/(16*115200);        // 115200 baud
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        5'd19:  o <= (pClkFreq*1e6)/(16*230400);        // 230400 baud
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        5'd20:  o <= (pClkFreq*1e6)/(16*406800);        // 460800 baud
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        5'd21:  o <= (pClkFreq*1e6)/(16*921600);        // 921600 baud
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        default:        o <= (pClkFreq*1e6)/(16*9600);  // 9600 baud
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        endcase
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endcase
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endmodule
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