// ============================================================================ // bus_task.v // __ // \\__/ o\ (C) 2014 Robert Finch, Stratford // \ __ / All rights reserved. // \/_// robfinch@finitron.ca // || // // This source file is free software: you can redistribute it and/or modify // it under the terms of the GNU Lesser General Public License as published // by the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // This source file is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY 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. If not, see . // // ============================================================================ // task opcode_read; begin vpa <= `TRUE; vda <= `TRUE; rwo <= `TRUE; ado <= pc; end endtask task insn_read; input [23:0] adr; begin vpa <= `TRUE; vda <= `FALSE; rwo <= `TRUE; ado <= adr; end endtask task data_read; input [23:0] adr; begin vpa <= `FALSE; vda <= `TRUE; rwo <= `TRUE; ado <= adr; end endtask task data_write; input [7:0] dat; begin vpa <= `FALSE; vda <= `TRUE; rwo <= `FALSE; ado <= wadr; dbo <= dat; end endtask task data_nack; begin vpa <= `FALSE; vda <= `FALSE; rwo <= `TRUE; ado <= 24'h000000; dbo <= 8'h00; end endtask