m3s003bo.v

another 8051 core porocesssor vhdl source code

    case (CMUX)
      1'b0 :
            begin
              LDATAA <= ACLDAT[7:0] ; 
            end
      1'b1 :
            begin
              LDATAA <= ALU_SUM ; 
            end
      default :
            begin
              LDATAA <= 8'bXXXXXXXX ; 
            end
    endcase 
  end 

  always @(ACCDAT or ACLDAT or NDIVAB)
  begin : set_loca
    case (NDIVAB)
      1'b0 :
            begin
              LOCALA <= ACCDAT[7] ; 
            end
      1'b1 :
            begin
              LOCALA <= ACLDAT[7] ; 
            end
      default :
            begin
              LOCALA <= 1'bx ; 
            end
    endcase 
  end 

  always @(CAM or ACLDAT or NMULAB)
  begin : set_locb
    case (NMULAB)
      1'b0 :
            begin
              LOCALB <= CAM ; 
            end
      1'b1 :
            begin
              LOCALB <= ACLDAT[9] ; 
            end
      default :
            begin
              LOCALB <= 1'bx ; 
            end
    endcase 
  end 

  always @(LOCALA or LDATAA or ACLDAT or LOCALB or ALUC)
  begin : set_locc
    case (ALUC[15])
      1'b0 :
            begin
              LOCALC <= LOCALA ; 
              LOCALD <= LDATAA[0] ; 
            end
      1'b1 :
            begin
              LOCALC <= ACLDAT[9] ; 
              LOCALD <= LOCALB ; 
            end
      default :
            begin
              LOCALC <= 1'bx ; 
              LOCALD <= 1'bx ; 
            end
    endcase 
  end 

  always @(CA or ACLDAT or ALUC)
  begin : set_loce
    case (ALUC[8])
      1'b0 :
            begin
              LOCALE <= ACLDAT[8] ; 
            end
      1'b1 :
            begin
              LOCALE <= CA ; 
            end
      default :
            begin
              LOCALE <= 1'bx ; 
            end
    endcase 
  end 

  always @(BC or ACLDAT or ALUC)
  begin : set_locf
    case (ALUC[16])
      1'b0 :
            begin
              LOCALF <= BC ; 
            end
      1'b1 :
            begin
              LOCALF <= ACLDAT[9] ; 
            end
      default :
            begin
              LOCALF <= 1'bx ; 
            end
    endcase 
  end 

  always @(LDATAA or LOCALC or LOCALD or ALUC)
  begin : set_alup
    case (ALUC[7:6])
      2'b00 :
            begin
              ALUP <= LDATAA ; 
            end
      2'b01 :
            begin
              ALUP[6:0] <= LDATAA[7:1] ; 
              ALUP[7] <= LOCALD ; 
            end
      2'b10 :
            begin
              ALUP[0] <= LOCALC ; 
              ALUP[7:1] <= LDATAA[6:0] ; 
            end
      2'b11 :
            begin
              ALUP[3:0] <= LDATAA[7:4] ; 
              ALUP[7:4] <= LDATAA[3:0] ; 
            end
      default :
            begin
              ALUP <= 8'bXXXXXXXX ; 
            end
    endcase 
  end 

  always @(ALUC or BD)
  begin : setmuxvect
    muxvect1[1:0] <= {ALUC[15], BD} ; 
  end 

  always @(LDATAA or CARI or EJ or muxvect1)
  begin : set_coout
    case (muxvect1[1:0])
      2'b00 :
            begin
              CO <= EJ ; 
            end
      2'b01 :
            begin
              CO <= CARI ; 
            end
      2'b10 :
            begin
              CO <= LDATAA[0] ; 
            end
      2'b11 :
            begin
              CO <= LDATAA[7] ; 
            end
      default :
            begin
              CO <= 1'bx ; 
            end
    endcase 
  end 

  always @(ACLDAT or BIT_POSN)
  begin : set_bbit
    case (BIT_POSN[2:0])
      3'b000 :
            begin
              LBBIT <= ACLDAT[0] ; 
            end
      3'b001 :
            begin
              LBBIT <= ACLDAT[1] ; 
            end
      3'b010 :
            begin
              LBBIT <= ACLDAT[2] ; 
            end
      3'b011 :
            begin
              LBBIT <= ACLDAT[3] ; 
            end
      3'b100 :
            begin
              LBBIT <= ACLDAT[4] ; 
            end
      3'b101 :
            begin
              LBBIT <= ACLDAT[5] ; 
            end
      3'b110 :
            begin
              LBBIT <= ACLDAT[6] ; 
            end
      3'b111 :
            begin
              LBBIT <= ACLDAT[7] ; 
            end
      default :
            begin
              LBBIT <= 1'bx ; 
            end
    endcase 
  end 

  always @(BC or BIT_POSN or ALUP or ALUC)
  begin : set_aludat
    if (ALUC[17])
    begin
      ALUDAT <= ALUP ; 
    end
    else
    begin
      case (BIT_POSN[2:0])
        3'b000 :
              begin
                ALUDAT[0] <= BC ; 
                ALUDAT[7:1] <= ALUP[7:1] ; 
              end
        3'b001 :
              begin
                ALUDAT[0] <= ALUP[0] ; 
                ALUDAT[1] <= BC ; 
                ALUDAT[7:2] <= ALUP[7:2] ; 
              end
        3'b010 :
              begin
                ALUDAT[1:0] <= ALUP[1:0] ; 
                ALUDAT[2] <= BC ; 
                ALUDAT[7:3] <= ALUP[7:3] ; 
              end
        3'b011 :
              begin
                ALUDAT[2:0] <= ALUP[2:0] ; 
                ALUDAT[3] <= BC ; 
                ALUDAT[7:4] <= ALUP[7:4] ; 
              end
        3'b100 :
              begin
                ALUDAT[3:0] <= ALUP[3:0] ; 
                ALUDAT[4] <= BC ; 
                ALUDAT[7:5] <= ALUP[7:5] ; 
              end
        3'b101 :
              begin
                ALUDAT[4:0] <= ALUP[4:0] ; 
                ALUDAT[5] <= BC ; 
                ALUDAT[7:6] <= ALUP[7:6] ; 
              end
        3'b110 :
              begin
                ALUDAT[5:0] <= ALUP[5:0] ; 
                ALUDAT[6] <= BC ; 
                ALUDAT[7] <= ALUP[7] ; 
              end
        3'b111 :
              begin
                ALUDAT[6:0] <= ALUP[6:0] ; 
                ALUDAT[7] <= BC ; 
              end
        default :
              begin
                ALUDAT <= 8'bXXXXXXXX ; 
              end
      endcase 
    end 
  end 

  always @(CH or EK or LDATAA or LOCALE or ALUC or LBBIT or NMULAB or NDIVAB)
  begin : genout
    ACO <= LOCALE ^ ALUC[5] ; 
    CPRDDM <= LDATAA ; 
    OV <= (EK & NMULAB & NDIVAB) | CH ; 
    BBIT <= LBBIT ; 
  end 
  //*********************************************************************
endmodule