Subversion Repositories t6507lp

        // SBC BCD

        // LDA

        alu_a = 0;

        alu_opcode = LDA_IMM;

        //$display("i = %d alu_opcode = %h alu_enable = %d", i, alu_opcode, alu_enable);

        //$display("op1 = %d op2 = %d  c = %d d = %d n = %d v = %d result = %d", alu_a, DUT.A, alu_status[C], alu_status[D], alu_status[N], alu_status[V], alu_result);

        @(negedge clk);

        alu_result_expected = 8'h00;

        //                       NV1BDIZC

        alu_status_expected[N] = 0;

        alu_status_expected[Z] = 1;

        check;

        // SED

        alu_opcode = SED_IMP;

        $display("A = %h B = %h X = %h Y = %h", alu_result, alu_a, alu_x, alu_y);

        @(negedge clk);

        alu_status_expected[D] = 1;

        check;

        // ADC

        alu_opcode = SBC_IMM;

        for (i = 0; i < 1000; i = i + 1)

        begin

                alu_a = $random;

                $display("A = %h B = %h C = %b X = %h Y = %h", alu_result, alu_a, alu_status_expected[C], alu_x, alu_y);

                @(negedge clk);

                C_temp = 0;

                sign   = alu_a[7];

                AL     = alu_a[3:0];

                AH     = alu_a[7:4];

                BL     = ~alu_result_expected[3:0];

                BH     = ~alu_result_expected[7:4];

                        BH = BH + 1;

                //$display("AL = %h BL = %h", AL, BL, );

                temp1 = AL + BL + alu_status_expected[C];

                //AH = A[7:4] + alu_a[7:4];

                temp2 = AH + BH;

                //$display("temp1 = %h temp2 = %h", temp1, temp2);

                if (temp1 > 9) begin

                        temp2 = temp2 + (temp1 / 10);

                        temp1 = temp1 % 10;

                end

                if (temp2 > 9) begin

                        alu_status_expected[C] = 1;

                        temp2 = temp2 % 10;

                end

                else begin

                        alu_status_expected[C] = 0;

                end

                //$display("bcdh2 = %d", bcdh2);

                //$display("bcdl = %d", bcdl);

                alu_result_expected = {temp2[3:0],temp1[3:0]};

                //{C_in,alu_result_expected[3:0]} = AL + BL + alu_status_expected[C];

                //{alu_status_expected[C],alu_result_expected[7:4]} = AH + BH + C_in;

                //if ( alu_result_expected[3:0] > 9 ) begin

                //      alu_result_expected[3:0] = alu_result_expected[3:0] - 10;

        //              alu_result_expected[7:4] = alu_result_expected[7:4] + 1;

                //end

                //if ( alu_result_expected[7:4] > 9 ) begin

                //      alu_result_expected[7:4] = alu_result_expected[7:4] - 10;

        //              alu_status_expected[C] = 1;

                //end

                alu_status_expected[Z] = (alu_result_expected == 0) ? 1 : 0;

                alu_status_expected[N] = alu_result_expected[7];

                alu_status_expected[V] = ((alu_a[7] == sign) && (alu_a[7] != alu_result_expected[7]));

                check;

        end

        //$stop;

        // CLD

        alu_opcode = CLD_IMP;

        @(negedge clk);

        alu_status_expected[D] = 0;

        check;