diff --git a/include/csu.h b/include/csu.h
index b64f4c8..8251c78 100644
--- a/include/csu.h
+++ b/include/csu.h
@@ -1,7 +1,10 @@
 #pragma once
+#include <sys/types.h>
+#include "concept.h"
 #ifndef CSU_H
 #include <array>
 #include <functional>
+#include <tuple>
 #include "tools.h"
 namespace ZYM {
 const int kROBSize = 32;
@@ -88,6 +91,105 @@ struct CentralScheduleUnit
  private:
   std::function<max_size_t(max_size_t)> instruction_fetcher;
   bool instruction_fetcher_initialized = false;
+  inline uint8_t ReadBit(uint32_t data, int pos) { return (data >> pos) & 1; }
+  inline void WriteBit(uint32_t &data, int pos, uint8_t bit) {
+    data &= ~(1 << pos);
+    data |= bit << pos;
+  }
+  std::tuple<dark::Bit<7 + 3 + 1>, dark::Bit<5>, dark::Bit<1>, dark::Bit<5>, dark::Bit<1>, dark::Bit<5>, dark::Bit<1>,
+             dark::Bit<32>, dark::Bit<6>>
+  Decode(max_size_t ins) {
+    // Decode the instruction
+    dark::Bit<7 + 3 + 1> full_ins_id;
+    dark::Bit<5> decoded_rd;
+    dark::Bit<1> has_decoded_rd;
+    dark::Bit<5> decoded_rs1;
+    dark::Bit<1> has_decoded_rs1;
+    dark::Bit<5> decoded_rs2;
+    dark::Bit<1> has_decoded_rs2;
+    dark::Bit<32> decoded_imm;
+    dark::Bit<6> decoded_shamt;
+    uint8_t opcode = ins & 0x7F;
+    if (opcode == 0b0110011) {
+      // R-type
+      has_decoded_rd = 1;
+      has_decoded_rs1 = 1;
+      has_decoded_rs2 = 1;
+      decoded_rd = ins >> 7 & 0x1F;
+      decoded_rs1 = ins >> 15 & 0x1F;
+      decoded_rs2 = ins >> 20 & 0x1F;
+      uint8_t funct3 = ins >> 12 & 0x7;
+      uint8_t funct7 = ins >> 25 & 0x7F;
+      full_ins_id = opcode | (funct3 << 7) | (((funct7 >> 5) & 1) << 10);
+    } else if (opcode == 0b1100111 || opcode == 0b0000011 || opcode == 0b0010011) {
+      // I-type
+      has_decoded_rd = 1;
+      has_decoded_rs1 = 1;
+      has_decoded_rs2 = 0;
+      decoded_rd = ins >> 7 & 0x1F;
+      decoded_rs1 = ins >> 15 & 0x1F;
+      decoded_imm = ins >> 20;
+      uint32_t sign_bit = ins >> 31;
+      if (sign_bit) {
+        decoded_imm = static_cast<uint32_t>(decoded_imm) | 0xFFFFF000;
+      }
+      uint8_t funct3 = ins >> 12 & 0x7;
+      uint8_t funct7 = ins >> 25 & 0x7F;
+      full_ins_id = opcode | (funct3 << 7) | (((funct7 >> 5) & 1) << 10);
+      decoded_shamt = ins >> 20 & 0x3F;
+    } else if (opcode == 0b0100011) {
+      // S-type
+      has_decoded_rd = 0;
+      has_decoded_rs1 = 1;
+      has_decoded_rs2 = 1;
+      decoded_rs1 = (ins >> 15) & 0x1F;
+      decoded_rs2 = (ins >> 20) & 0x1F;
+      decoded_imm = ((ins >> 7) & 0x1F) | ((ins >> 25) << 5);
+      uint32_t sign_bit = ins >> 31;
+      if (sign_bit) {
+        decoded_imm = static_cast<uint32_t>(decoded_imm) | 0xFFFFF000;
+      }
+      uint8_t funct3 = ins >> 12 & 0x7;
+      full_ins_id = opcode | (funct3 << 7);
+    } else if (opcode == 0b1100011) {
+      // B-type
+      has_decoded_rd = 0;
+      has_decoded_rs1 = 1;
+      has_decoded_rs2 = 1;
+      decoded_rs1 = (ins >> 15) & 0x1F;
+      decoded_rs2 = (ins >> 20) & 0x1F;
+      decoded_imm = (((ins >> 8) & 0xF) << 1) | (((ins >> 25) & 0x3F) << 5) | (((ins >> 7) & 0x1) << 11) |
+                    (((ins >> 31) & 0x1) << 12);
+      uint32_t sign_bit = ins >> 31;
+      if (sign_bit) {
+        decoded_imm = static_cast<uint32_t>(decoded_imm) | 0xFFFFE000;
+      }
+      uint8_t funct3 = ins >> 12 & 0x7;
+      full_ins_id = opcode | (funct3 << 7);
+    } else if(opcode==0b0110111) {
+      // U-type
+      has_decoded_rd = 1;
+      has_decoded_rs1 = 0;
+      has_decoded_rs2 = 0;
+      decoded_rd = ins >> 7 & 0x1F;
+      decoded_imm = ins >> 12;
+      full_ins_id = opcode;
+    } else if(opcode==0b1101111) {
+      // J-type
+      has_decoded_rd = 1;
+      has_decoded_rs1 = 0;
+      has_decoded_rs2 = 0;
+      decoded_rd = ins >> 7 & 0x1F;
+      decoded_imm = (ins & 0xFF000) | (((ins >> 20) & 1)<<11) | (((ins >> 21) & 0x3FF)<<1) | ((ins >> 31) << 20);
+      uint32_t sign_bit = ins >> 31;
+      if (sign_bit) {
+        decoded_imm = static_cast<uint32_t>(decoded_imm) | 0xFFE00000;
+      }
+      full_ins_id = opcode;
+    } else throw std::runtime_error("Unknown instruction in Decode");
+    return std::make_tuple(full_ins_id, decoded_rd, has_decoded_rd, decoded_rs1, has_decoded_rs1, decoded_rs2,
+                           has_decoded_rs2, decoded_imm, decoded_shamt);
+  }
 
  public:
   CentralScheduleUnit() { ; }
diff --git a/include/reservestation.h b/include/reservestation.h
index 3b2b6c1..58e6bf0 100644
--- a/include/reservestation.h
+++ b/include/reservestation.h
@@ -50,6 +50,7 @@ struct ReserveStation_Output {
   dark::Register<7 + 3 + 1> request_full_id;
   dark::Register<32> operand1;
   dark::Register<32> operand2;
+  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 8452511..a2b6c06 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -149,6 +149,7 @@ int main(int argc, char **argv) {
   RWConnect(rs.operand1, alu.operand1);
   RWConnect(rs.operand2, alu.operand2);
   RWConnect(rs.request_ROB_index, alu.request_ROB_index);
+  RWConnect(rs.alu_ins_PC, alu.request_PC);
   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);