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[/] [xulalx25soc/] [trunk/] [rtl/] [wbutohex.v] - Rev 89
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//////////////////////////////////////////////////////////////////////////////// // // Filename: wbutohex.v // // Project: XuLA2-LX25 SoC based upon the ZipCPU // // Purpose: Supports a printable character conversion from a printable // ASCII character to six bits of valid data. The encoding is // as follows: // // 0-9 -> 0-9 // A-Z -> 10-35 // a-z -> 36-61 // @ -> 62 // % -> 63 // // Note that decoding is stateless, yet requires one clock. // // // Creator: Dan Gisselquist, Ph.D. // Gisselquist Technology, LLC // //////////////////////////////////////////////////////////////////////////////// // // Copyright (C) 2015-2016, Gisselquist Technology, LLC // // This program is free software (firmware): you can redistribute it and/or // modify it under the terms of the GNU General Public License as published // by the Free Software Foundation, either version 3 of the License, or (at // your option) any later version. // // This program is distributed in the hope that it will be useful, but WITHOUT // ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License along // with this program. (It's in the $(ROOT)/doc directory, run make with no // target there if the PDF file isn't present.) If not, see // <http://www.gnu.org/licenses/> for a copy. // // License: GPL, v3, as defined and found on www.gnu.org, // http://www.gnu.org/licenses/gpl.html // // //////////////////////////////////////////////////////////////////////////////// // // module wbutohex(i_clk, i_stb, i_byte, o_stb, o_valid, o_hexbits); input i_clk, i_stb; input [7:0] i_byte; output reg o_stb, o_valid; output reg [5:0] o_hexbits; always @(posedge i_clk) o_stb <= i_stb; always @(posedge i_clk) begin // These are the defaults, to be overwridden by the ifs below o_valid <= 1'b1; o_hexbits <= 6'h00; if ((i_byte >= 8'h30)&&(i_byte <= 8'h39)) // A digit o_hexbits <= { 2'b0, i_byte[3:0] }; else if ((i_byte >= 8'h41)&&(i_byte <= 8'h5a)) // Upper case o_hexbits <= (i_byte[5:0] - 6'h01 + 6'h0a);// -'A'+10 else if ((i_byte >= 8'h61)&&(i_byte <= 8'h7a)) o_hexbits <= (i_byte[5:0] +6'h03); // -'a'+(10+26) else if (i_byte == 8'h40) // An '@' sign o_hexbits <= 6'h3e; else if (i_byte == 8'h25) // A '%' sign o_hexbits <= 6'h3f; else o_valid <= 1'b0; end endmodule
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