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[/] [rtf65002/] [trunk/] [rtl/] [verilog/] [byte_irq.v] - Blame information for rev 5

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1 5 robfinch 
// IRQ processing states
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// The high order PC[31:16] is set to zero, forcing the IRQ routine to be in bank zero.
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//
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BYTE_IRQ1:
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        if (ack_i) begin
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                cyc_o <= 1'b0;
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                stb_o <= 1'b0;
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                we_o <= 1'b0;
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                sel_o <= 4'h0;
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                sp <= sp_dec;
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                if (dhit) begin
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                        wrsel <= sel_o;
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                        wr <= 1'b1;
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                end
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                state <= BYTE_IRQ2;
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        end
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BYTE_IRQ2:
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        begin
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                radr <= {24'h1,sp[7:2]};
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                radr2LSB <= sp[1:0];
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                wadr <= {24'h1,sp[7:2]};
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                wadr2LSB <= sp[1:0];
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                wdat <= {4{pc[23:16]}};
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                cyc_o <= 1'b1;
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                stb_o <= 1'b1;
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                we_o <= 1'b1;
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                case(sp[1:0])
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                2'd0:   sel_o <= 4'b0001;
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                2'd1:   sel_o <= 4'b0010;
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                2'd2:   sel_o <= 4'b0100;
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                2'd3:   sel_o <= 4'b1000;
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                endcase
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                adr_o <= {24'h1,sp[7:2],2'b00};
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                dat_o <= {4{pc[23:16]}};
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                state <= BYTE_IRQ3;
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        end
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BYTE_IRQ3:
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        if (ack_i) begin
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                cyc_o <= 1'b0;
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                stb_o <= 1'b0;
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                we_o <= 1'b0;
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                sel_o <= 4'h0;
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                sp <= sp_dec;
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                if (dhit) begin
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                        wrsel <= sel_o;
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                        wr <= 1'b1;
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                end
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                state <= BYTE_IRQ4;
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        end
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BYTE_IRQ4:
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        begin
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                radr <= {24'h1,sp[7:2]};
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                radr2LSB <= sp[1:0];
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                wadr <= {24'h1,sp[7:2]};
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                wadr2LSB <= sp[1:0];
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                wdat <= {4{pc[15:8]}};
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                cyc_o <= 1'b1;
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                stb_o <= 1'b1;
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                we_o <= 1'b1;
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                case(sp[1:0])
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                2'd0:   sel_o <= 4'b0001;
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                2'd1:   sel_o <= 4'b0010;
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                2'd2:   sel_o <= 4'b0100;
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                2'd3:   sel_o <= 4'b1000;
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                endcase
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                adr_o <= {24'h1,sp[7:2],2'b00};
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                dat_o <= {4{pc[15:8]}};
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                state <= BYTE_IRQ5;
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        end
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BYTE_IRQ5:
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        if (ack_i) begin
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                cyc_o <= 1'b0;
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                stb_o <= 1'b0;
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                we_o <= 1'b0;
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                sel_o <= 4'h0;
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                sp <= sp_dec;
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                if (dhit) begin
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                        wrsel <= sel_o;
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                        wr <= 1'b1;
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                end
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                state <= BYTE_IRQ6;
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        end
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BYTE_IRQ6:
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        begin
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                radr <= {24'h1,sp[7:2]};
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                radr2LSB <= sp[1:0];
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                wadr <= {24'h1,sp[7:2]};
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                wadr2LSB <= sp[1:0];
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                wdat <= {4{pc[7:0]}};
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                cyc_o <= 1'b1;
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                stb_o <= 1'b1;
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                we_o <= 1'b1;
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                case(sp[1:0])
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                2'd0:   sel_o <= 4'b0001;
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                2'd1:   sel_o <= 4'b0010;
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                2'd2:   sel_o <= 4'b0100;
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                2'd3:   sel_o <= 4'b1000;
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                endcase
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                adr_o <= {24'h1,sp[7:2],2'b00};
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                dat_o <= {4{pc[7:0]}};
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                state <= BYTE_IRQ7;
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        end
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BYTE_IRQ7:
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        if (ack_i) begin
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                cyc_o <= 1'b0;
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                stb_o <= 1'b0;
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                we_o <= 1'b0;
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                sel_o <= 4'h0;
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                sp <= sp_dec;
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                if (dhit) begin
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                        wrsel <= sel_o;
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                        wr <= 1'b1;
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                end
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                state <= BYTE_IRQ8;
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        end
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BYTE_IRQ8:
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        begin
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                radr <= {24'h1,sp[7:2]};
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                radr2LSB <= sp[1:0];
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                wadr <= {24'h1,sp[7:2]};
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                wadr2LSB <= sp[1:0];
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                wdat <= {4{sr8[7:0]}};
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                cyc_o <= 1'b1;
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                stb_o <= 1'b1;
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                we_o <= 1'b1;
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                case(sp[1:0])
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                2'd0:   sel_o <= 4'b0001;
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                2'd1:   sel_o <= 4'b0010;
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                2'd2:   sel_o <= 4'b0100;
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                2'd3:   sel_o <= 4'b1000;
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                endcase
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                adr_o <= {24'h1,sp[7:2],2'b00};
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                dat_o <= {4{sr8[7:0]}};
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                state <= BYTE_IRQ9;
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        end
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BYTE_IRQ9:
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        if (ack_i) begin
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                cyc_o <= 1'b0;
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                stb_o <= 1'b0;
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                we_o <= 1'b0;
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                sel_o <= 4'h0;
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                sp <= sp_dec;
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                if (dhit) begin
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                        wrsel <= sel_o;
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                        wr <= 1'b1;
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                end
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                pc[31:16] <= 16'h0000;
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                radr <= vect[31:2];
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                radr2LSB <= vect[1:0];
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                state <= BYTE_JMP_IND1;
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        end
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