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// ============================================================================
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// __
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// \\__/ o\ (C) 2014 Robert Finch, Stratford
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// \ __ / All rights reserved.
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// \/_// robfinch<remove>@opencores.org
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// ||
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//
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// This source file is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published
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// by the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This source file is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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//
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// ============================================================================
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//
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task set_sp;
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begin
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if (m816) begin
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radr <= {8'h00,sp[15:0]};
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wadr <= {8'h00,sp[15:0]};
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sp <= sp_dec;
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end
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else begin
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radr <= {16'h0001,sp[7:0]};
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wadr <= {16'h0001,sp[7:0]};
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sp[7:0] <= sp[7:0] - 8'd1;
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sp[15:8] <= 8'h1;
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end
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end
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endtask
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task inc_sp;
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begin
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if (m816) begin
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radr <= {8'h00,sp_inc[15:0]};
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sp <= sp_inc;
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end
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else begin
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radr <= {16'h0001,sp_inc[7:0]};
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sp <= {8'h1,sp_inc[7:0]};
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end
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end
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endtask
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task tsk_push;
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input [5:0] SW8;
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input [5:0] SW16;
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input szFlg;
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begin
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if (m816) begin
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if (szFlg) begin
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radr <= {8'h00,sp_dec[15:0]};
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wadr <= {8'h00,sp_dec[15:0]};
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store_what <= SW16;
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sp <= sp_dec2;
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end
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else begin
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radr <= {8'h00,sp[15:0]};
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wadr <= {8'h00,sp[15:0]};
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store_what <= SW8;
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sp <= sp_dec;
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end
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end
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else begin
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radr <= {16'h01,sp[7:0]};
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wadr <= {16'h01,sp[7:0]};
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store_what <= SW8;
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sp[7:0] <= sp[7:0] - 8'd1;
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sp[15:8] <= 8'h1;
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end
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state <= STORE1;
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end
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endtask
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task moveto_ifetch;
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begin
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vpa <= `TRUE;
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vda <= `TRUE;
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ado <= pc;
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next_state(IFETCH1);
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end
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endtask
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