diff --git a/include/alu.h b/include/alu.h
index 69e4cbd..6bd143d 100644
--- a/include/alu.h
+++ b/include/alu.h
@@ -1,4 +1,5 @@
 #pragma once
+#include "concept.h"
 #ifndef ALU_H
 #include "tools.h"
 namespace ZYM {
@@ -6,6 +7,8 @@ struct ALU_Input {
   dark::Wire<7 + 3 + 1> request_full_id;
   dark::Wire<32> operand1;
   dark::Wire<32> operand2;
+  dark::Wire<32> imm;
+  dark::Wire<6> shamt;
   dark::Wire<5> request_ROB_index;
   dark::Wire<32> request_PC;
 };
@@ -20,7 +23,307 @@ struct ALU : public dark::Module<ALU_Input, ALU_Output> {
     // Constructor
   }
   void work() {
-    // Update function
+    switch (static_cast<max_size_t>(request_full_id)) {
+      case 0: {
+        alu_status <= 0b01;
+        return;
+      }
+      case 0b00000000001: {
+        // fake instruction of halt
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        return;
+      }
+      case 0b00000110111: {
+        // lui
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= imm;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00000010111: {
+        // auipc
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(request_PC) + imm;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00001101111: {
+        // jal
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(request_PC) + 4;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        return;
+      }
+      case 0b00001100111: {
+        // jalr
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(request_PC) + 4;
+        completed_alu_resulting_PC <= ((static_cast<max_size_t>(operand1) + static_cast<max_size_t>(imm)) & 0xfffffffe);
+        return;
+      }
+      case 0b00001100011: {
+        // beq
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) == static_cast<max_size_t>(operand2)) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b00011100011: {
+        // bne
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) != static_cast<max_size_t>(operand2)) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b01001100011: {
+        // blt
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<int32_t>(static_cast<max_size_t>(operand1)) <
+            static_cast<int32_t>(static_cast<max_size_t>(operand2))) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b01011100011: {
+        // bge
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<int32_t>(static_cast<max_size_t>(operand1)) >=
+            static_cast<int32_t>(static_cast<max_size_t>(operand2))) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b01101100011: {
+        // bltu
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) < static_cast<max_size_t>(operand2)) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b01111100011: {
+        // bgeu
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) >= static_cast<max_size_t>(operand2)) {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + imm;
+        } else {
+          completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        }
+        return;
+      }
+      case 0b00000010011: {
+        // addi
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(operand1) + imm;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00100010011: {
+        // slti
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<int32_t>(static_cast<max_size_t>(operand1)) <
+            static_cast<int32_t>(static_cast<max_size_t>(imm))) {
+          result <= 1;
+        } else {
+          result <= 0;
+        }
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00110010011: {
+        // sltiu
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) < static_cast<max_size_t>(imm)) {
+          result <= 1;
+        } else {
+          result <= 0;
+        }
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01000010011: {
+        // xori
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) ^ static_cast<max_size_t>(imm));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01100010011: {
+        // ori
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) | static_cast<max_size_t>(imm));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01110010011: {
+        // andi
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) & static_cast<max_size_t>(imm));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00010010011: {
+        // slli
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) << static_cast<max_size_t>(shamt));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01010010011: {
+        // srli
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) >> static_cast<max_size_t>(shamt));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b11010010011: {
+        // srai
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        uint32_t res_tmp = static_cast<max_size_t>(operand1) >> static_cast<max_size_t>(shamt);
+        uint8_t sign = (static_cast<max_size_t>(operand1) >> 31) & 1;
+        if (sign) {
+          for (size_t i = 0; i < static_cast<max_size_t>(shamt); i++) {
+            res_tmp |= 1 << (31 - i);
+          }
+        }
+        result <= res_tmp;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00000110011: {
+        // add
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(operand1) + static_cast<max_size_t>(operand2);
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b10000110011: {
+        // sub
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= static_cast<max_size_t>(operand1) - static_cast<max_size_t>(operand2);
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00010110011: {
+        // sll
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        uint8_t actual_shamt = static_cast<max_size_t>(operand2) & 0b11111;
+        result <= (static_cast<max_size_t>(operand1) << actual_shamt);
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00100110011: {
+        // slt
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<int32_t>(static_cast<max_size_t>(operand1)) <
+            static_cast<int32_t>(static_cast<max_size_t>(operand2))) {
+          result <= 1;
+        } else {
+          result <= 0;
+        }
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b00110110011: {
+        // sltu
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        if (static_cast<max_size_t>(operand1) < static_cast<max_size_t>(operand2)) {
+          result <= 1;
+        } else {
+          result <= 0;
+        }
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01000110011: {
+        // xor
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) ^ static_cast<max_size_t>(operand2));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01010110011: {
+        // srl
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        uint8_t actual_shamt = static_cast<max_size_t>(operand2) & 0b11111;
+        result <= (static_cast<max_size_t>(operand1) >> actual_shamt);
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b11010110011: {
+        // sra
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        uint8_t actual_shamt = static_cast<max_size_t>(operand2) & 0b11111;
+        uint32_t res_tmp = static_cast<max_size_t>(operand1) >> actual_shamt;
+        uint8_t sign = (static_cast<max_size_t>(operand1) >> 31) & 1;
+        if (sign) {
+          for (size_t i = 0; i < actual_shamt; i++) {
+            res_tmp |= 1 << (31 - i);
+          }
+        }
+        result <= res_tmp;
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01100110011: {
+        // or
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) | static_cast<max_size_t>(operand2));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      case 0b01110110011: {
+        // and
+        alu_status <= 0b10;
+        result_ROB_index <= request_ROB_index;
+        result <= (static_cast<max_size_t>(operand1) & static_cast<max_size_t>(operand2));
+        completed_alu_resulting_PC <= static_cast<max_size_t>(request_PC) + 4;
+        return;
+      }
+      default:
+        throw std::runtime_error("Invalid instruction occured in ALU");
+    }
   }
 };
 }  // namespace ZYM
diff --git a/include/reservestation.h b/include/reservestation.h
index 58e6bf0..a71c32f 100644
--- a/include/reservestation.h
+++ b/include/reservestation.h
@@ -50,6 +50,8 @@ struct ReserveStation_Output {
   dark::Register<7 + 3 + 1> request_full_id;
   dark::Register<32> operand1;
   dark::Register<32> operand2;
+  dark::Register<32> op_imm;
+  dark::Register<6> op_shamt;
   dark::Register<32> alu_ins_PC;
   dark::Register<5> request_ROB_index;
   dark::Register<6> RS_remain_space_output;
diff --git a/src/main.cpp b/src/main.cpp
index a2b6c06..f9ee329 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -150,6 +150,8 @@ int main(int argc, char **argv) {
   RWConnect(rs.operand2, alu.operand2);
   RWConnect(rs.request_ROB_index, alu.request_ROB_index);
   RWConnect(rs.alu_ins_PC, alu.request_PC);
+  RWConnect(rs.op_imm, alu.imm);
+  RWConnect(rs.op_shamt, alu.shamt);
   RWConnect(alu.alu_status, rs.alu_status_receiver);
   RWConnect(alu.result_ROB_index, rs.completed_aluins_ROB_index);
   RWConnect(alu.result, rs.completed_aluins_result);