// ============================================================================
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// ============================================================================
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// __
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// __
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// \\__/ o\ (C) 2005-2022 Robert Finch, Waterloo
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// \\__/ o\ (C) 2005-2023 Robert Finch, Waterloo
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// \ __ / All rights reserved.
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// \ __ / All rights reserved.
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// \/_// robfinch@finitron.ca
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// \/_// robfinch@finitron.ca
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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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// BSD 3-Clause License
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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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// 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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// modification, are permitted provided that the following conditions are met:
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//
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//
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// 1. Redistributions of source code must retain the above copyright notice, this
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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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// list of conditions and the following disclaimer.
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//
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//
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// 2. Redistributions in binary form must reproduce the above copyright notice,
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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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// 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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// and/or other materials provided with the distribution.
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//
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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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// 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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// 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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// this software without specific prior written permission.
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//
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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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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// 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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// 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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// 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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// 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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// 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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// 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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// 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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// 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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// 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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// ============================================================================
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//
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//
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module uart6551BaudLUT(a, o);
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module uart6551BaudLUT(a, o);
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parameter pClkFreq = 100;
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parameter pClkFreq = 100;
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parameter pCounterBits = 24;
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parameter pCounterBits = 24;
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input [4:0] a;
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input [4:0] a;
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output reg [pCounterBits-1:0] o;
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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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// table for a 50.000MHz reference clock
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// value = 50,000,000 / (baud * 16)
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// value = 50,000,000 / (baud * 16)
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always_comb
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always_comb
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if (pClkFreq==40)
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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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case (a) // synopsys full_case parallel_case
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5'd0: o <= 0;
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5'd0: o <= 0;
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5'd1: o <= 24'd50000; // 50 baud
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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'd2: o <= 24'd33333; // 75 baud
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5'd3: o <= 24'd22744; // 109.92 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'd4: o <= 24'd18576; // 134.58 baud
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5'd5: o <= 24'd16667; // 150 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'd6: o <= 24'd8333; // 300 baud
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5'd7: o <= 24'd4167; // 600 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'd8: o <= 24'd2083; // 1200 baud
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5'd9: o <= 24'd1389; // 1800 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'd10: o <= 24'd1042; // 2400 baud
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5'd11: o <= 24'd694; // 3600 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'd12: o <= 24'd521; // 4800 baud
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5'd13: o <= 24'd347; // 7200 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'd14: o <= 24'd260; // 9600 baud
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5'd15: o <= 24'd130; // 19200 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'd16: o <= 24'd65; // 38400 baud
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5'd17: o <= 24'd43; // 57600 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'd18: o <= 24'd22; // 115200 baud
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5'd19: o <= 24'd11; // 230400 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'd20: o <= 24'd5; // 460800 baud
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5'd21: o <= 24'd3; // 921600 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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default: o <= 24'd260; // 9600 baud
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endcase
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endcase
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else if (pClkFreq==50)
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50:
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case (a) // synopsys full_case parallel_case
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case (a) // synopsys full_case parallel_case
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5'd0: o <= 0;
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5'd0: o <= 0;
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5'd1: o <= 24'd62500; // 50 baud
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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'd2: o <= 24'd41667; // 75 baud
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5'd3: o <= 24'd28617; // 109.92 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'd4: o <= 24'd23220; // 134.58 baud
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5'd5: o <= 24'd20833; // 150 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'd6: o <= 24'd10417; // 300 baud
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5'd7: o <= 24'd5208; // 600 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'd8: o <= 24'd2604; // 1200 baud
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5'd9: o <= 24'd1736; // 1800 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'd10: o <= 24'd1302; // 2400 baud
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5'd11: o <= 24'd868; // 3600 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'd12: o <= 24'd651; // 4800 baud
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5'd13: o <= 24'd434; // 7200 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'd14: o <= 24'd326; // 9600 baud
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5'd15: o <= 24'd163; // 19200 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'd16: o <= 24'd81; // 38400 baud
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5'd17: o <= 24'd54; // 57600 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'd18: o <= 24'd27; // 115200 baud
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5'd19: o <= 24'd14; // 230400 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'd20: o <= 24'd7; // 460800 baud
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5'd21: o <= 24'd3; // 921600 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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default: o <= 24'd326; // 9600 baud
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endcase
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endcase
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else if (pClkFreq==80)
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80:
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case (a) // synopsys full_case parallel_case
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case (a) // synopsys full_case parallel_case
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5'd0: o <= 0;
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5'd0: o <= 0;
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5'd1: o <= 24'd100000; // 50 baud
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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'd2: o <= 24'd66667; // 75 baud
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5'd3: o <= 24'd45488; // 109.92 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'd4: o <= 24'd37153; // 134.58 baud
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5'd5: o <= 24'd33333; // 150 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'd6: o <= 24'd16667; // 300 baud
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5'd7: o <= 24'd8333; // 600 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'd8: o <= 24'd4167; // 1200 baud
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5'd9: o <= 24'd2778; // 1800 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'd10: o <= 24'd2083; // 2400 baud
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5'd11: o <= 24'd1389; // 3600 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'd12: o <= 24'd1042; // 4800 baud
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5'd13: o <= 24'd694; // 7200 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'd14: o <= 24'd521; // 9600 baud
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5'd15: o <= 24'd260; // 19200 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'd16: o <= 24'd130; // 38400 baud
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5'd17: o <= 24'd87; // 57600 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'd18: o <= 24'd43; // 115200 baud
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5'd19: o <= 24'd22; // 230400 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'd20: o <= 24'd11; // 460800 baud
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5'd21: o <= 24'd5; // 921600 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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default: o <= 24'd521; // 9600 baud
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endcase
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endcase
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else if (pClkFreq==100)
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100:
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case (a) // synopsys full_case parallel_case
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case (a) // synopsys full_case parallel_case
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5'd0: o <= 0;
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5'd0: o <= 0;
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5'd1: o <= 24'd125000; // 50 baud
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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'd2: o <= 24'd83333; // 75 baud
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5'd3: o <= 24'd56860; // 109.92 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'd4: o <= 24'd46441; // 134.58 baud
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5'd5: o <= 24'd41667; // 150 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'd6: o <= 24'd20833; // 300 baud
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5'd7: o <= 24'd10417; // 600 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'd8: o <= 24'd5208; // 1200 baud
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5'd9: o <= 24'd3472; // 1800 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'd10: o <= 24'd2604; // 2400 baud
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5'd11: o <= 24'd1736; // 3600 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'd12: o <= 24'd1302; // 4800 baud
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5'd13: o <= 24'd868; // 7200 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'd14: o <= 24'd651; // 9600 baud
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5'd15: o <= 24'd326; // 19200 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'd16: o <= 24'd163; // 38400 baud
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5'd17: o <= 24'd109; // 57600 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'd18: o <= 24'd54; // 115200 baud
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5'd19: o <= 24'd27; // 230400 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'd20: o <= 24'd14; // 460800 baud
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5'd21: o <= 24'd7; // 921600 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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default: o <= 24'd651; // 9600 baud
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endcase
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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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endmodule
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