| Line 165... |
Line 165... |
begin
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begin
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alu_status[Z] <= STATUS[Z];
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alu_status[Z] <= STATUS[Z];
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alu_status[V] <= alu_a[6];
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alu_status[V] <= alu_a[6];
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alu_status[N] <= alu_a[7];
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alu_status[N] <= alu_a[7];
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end
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end
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INC_ZPG, INC_ZPX, INC_ABS, INC_ABX, DEC_ZPG, DEC_ZPX, DEC_ABS, DEC_ABX :
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INC_ZPG, INC_ZPX, INC_ABS, INC_ABX, DEC_ZPG, DEC_ZPX, DEC_ABS, DEC_ABX, ASL_ZPG, ASL_ZPX, ASL_ABS, ASL_ABX :
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begin
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begin
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alu_result <= result;
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alu_result <= result;
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alu_status <= STATUS;
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alu_status <= STATUS;
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|
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end
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end
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default : begin
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default : begin
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//$display("ERROR");
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//$display("ERROR");
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end
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end
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endcase
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endcase
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| Line 389... |
Line 388... |
STATUS[V] = 0;
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STATUS[V] = 0;
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end
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end
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|
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// ASL - Arithmetic Shift Left
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// ASL - Arithmetic Shift Left
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ASL_ACC : begin
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ASL_ACC : begin
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{STATUS[C],result} = A << 1;
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//{STATUS[C],result} = A << 1;
|
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{STATUS[C],result} = {A,1'b0};
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end
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end
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ASL_ZPG, ASL_ZPX, ASL_ABS, ASL_ABX : begin
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ASL_ZPG, ASL_ZPX, ASL_ABS, ASL_ABX : begin
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{STATUS[C],result} = alu_a << 1;
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//{STATUS[C],result} = alu_a << 1;
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{STATUS[C],result} = {alu_a,1'b0};
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end
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end
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|
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// LSR - Logical Shift Right
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// LSR - Logical Shift Right
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LSR_ACC: begin
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LSR_ACC: begin
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{result, STATUS[C]} = A >> 1;
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//{result, STATUS[C]} = A >> 1;
|
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{result,STATUS[C]} = {1'b0,A};
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end
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end
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LSR_ZPG, LSR_ZPX, LSR_ABS, LSR_ABX : begin
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LSR_ZPG, LSR_ZPX, LSR_ABS, LSR_ABX : begin
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{result, STATUS[C]} = alu_a >> 1;
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//{result, STATUS[C]} = alu_a >> 1;
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{result,STATUS[C]} = {1'b0,alu_a};
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end
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end
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|
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// ROL - Rotate Left
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// ROL - Rotate Left
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ROL_ACC : begin
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ROL_ACC : begin
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{STATUS[C],result} = {A,alu_status[C]}; //TODO: does it really work?
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{STATUS[C],result} = {A,alu_status[C]}; //TODO: does it really work?
|
