计组实验

根据opcode生成控制信号 不同类型指令方式不同（查表）

//识别不同类型指令
// r format 0110011
wire rtype  = ~Op[6]&Op[5]&Op[4]&~Op[3]&~Op[2]&Op[1]&Op[0]; //0110011 
    wire i_add  = rtype& ~Funct7[6]&~Funct7[5]&~Funct7[4]&~Funct7[3]&~Funct7[2]&~Funct7[1]&~Funct7[0]&~Funct3[2]&~Funct3[1]&~Funct3[0]; // add 0000000 000
...

// 生成控制信号
  assign RegWrite   = rtype | itype_r | LUI | itype_l; // register write
  assign MemWrite   = stype;                           // memory write
  assign ALUSrc     = itype_r | LUI | itype_l | stype;   // ALU B is from instruction immediate

//EXTOp 立即数操作信号 EXT.v查看具体实现
  // EXT_CTRL_ITYPE_SHAMT 6'b100000
  // EXT_CTRL_ITYPE	      6'b010000
  // EXT_CTRL_STYPE	      6'b001000
  // EXT_CTRL_BTYPE	      6'b000100
  // EXT_CTRL_UTYPE	      6'b000010
  // EXT_CTRL_JTYPE	      6'b000001
  assign EXTOp[5]    = 0;
  assign EXTOp[4]    = i_addi | itype_l | i_andi;
  assign EXTOp[3]    = stype; 
  assign EXTOp[2]    = sbtype; 
  assign EXTOp[1]    = LUI;
  assign EXTOp[0]    = i_jal;   

//用于选择写回寄存器的数据来源
  // WDSel_FromALU 2'b00
  // WDSel_FromMEM 2'b01
  // WDSel_FromPC  2'b10
    assign WDSel[1] = i_jal | i_jalr;
    assign WDSel[0] = itype_l;