diff --git a/hs/Execute.hs b/hs/Execute.hs
index 2694391..020311c 100644
--- a/hs/Execute.hs
+++ b/hs/Execute.hs
@@ -5,19 +5,208 @@ module Execute(execute) where
 
 import Clash.Prelude
 import Decode(DecodeResult(..))
-import DecodeTypes(Opcode(..))
-
+import DecodeTypes(
+    Opcode(..),
+    RTypeFields(..), ITypeFields(..), STypeFields(..),
+    BTypeFields(..), UTypeFields(..), JTypeFields(..)
+  )
 import Types(Addr, DoubleWord)
+import Exceptions(Exception(..))
 import BusTypes(
     WriteRequest(..),
     ReadRequest(..),
+    TransactionSize(..),
+    BusVal(..)
   )
-import RegFiles(RegFileIdx)
+import RegFiles(RegFileIdx, RegVal(..))
 import Util((|>))
 
 data ExecuteResult  = ReadRequest {readRequest :: ReadRequest, insnAddr :: Addr}
                     | WriteRequest {writeRequest :: WriteRequest, insnAddr :: Addr}
                     | WriteBackGPR  {idx :: RegFileIdx, val :: DoubleWord}
+                    | Jump         { targetAddr :: Addr }
+                    | DecodeException {exception :: Exception, insnAddr :: Addr}
+                    | InstructionException {exception :: Exception, insnAddr :: Addr}
+                    deriving (Generic, Show, Eq, NFDataX)
 
+-- Helper functions to extract values from RegVal
+extractRegVal :: RegVal -> DoubleWord
+extractRegVal (Value _ val) = val
+extractRegVal (Unpopulated _) = undefined
+
+-- Execute function
 execute :: DecodeResult -> ExecuteResult
-execute = undefined
\ No newline at end of file
+execute (Opcode opcode addr) = case opcode of
+  -- R-Type Instructions
+  ADD  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 + val2)
+  SUB  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 - val2)
+  XOR  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 `xor` val2)
+  OR   (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 .|. val2)
+  AND  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 .&. val2)
+  SLL  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 `shiftL` fromIntegral (val2 .&. 0x3F))
+  SRL  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (val1 `shiftR` fromIntegral (val2 .&. 0x3F))
+  SRA  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (bitCoerce (val1 `shiftR` fromIntegral (val2 .&. 0x3F)))
+  SLT  (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        val2 = unpack (pack (extractRegVal rs2) :: BitVector 64) :: Signed 64
+    in WriteBackGPR rd (if val1 < val2 then 1 else 0)
+  SLTU (RTypeFields rd _ rs1 rs2 _) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+    in WriteBackGPR rd (if val1 < val2 then 1 else 0)
+
+  -- I-Type Instructions
+  ADDI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        immVal = signExtend imm
+    in WriteBackGPR rd (val1 + immVal)
+  XORI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        immVal = signExtend imm
+    in WriteBackGPR rd (val1 `xor` immVal)
+  ORI   (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        immVal = signExtend imm
+    in WriteBackGPR rd (val1 .|. immVal)
+  ANDI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        immVal = signExtend imm
+    in WriteBackGPR rd (val1 .&. immVal)
+  SLLI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        shamt = imm .&. 0x3F
+    in WriteBackGPR rd (val1 `shiftL` fromIntegral shamt)
+  SRLI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        shamt = imm .&. 0x3F
+    in WriteBackGPR rd (val1 `shiftR` fromIntegral shamt)
+  SRAI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        shamt = imm .&. 0x3F
+    in WriteBackGPR rd (bitCoerce (val1 `shiftR` fromIntegral shamt))
+  SLTI  (ITypeFields rd _ rs1 imm) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        immVal = unpack (pack (signExtend imm) :: BitVector 64) :: Signed 64
+    in WriteBackGPR rd (if val1 < immVal then 1 else 0)
+  SLTIU (ITypeFields rd _ rs1 imm) ->
+    let val1 = extractRegVal rs1
+        immVal = signExtend imm
+    in WriteBackGPR rd (if val1 < immVal then 1 else 0)
+  LB    (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+    in Execute.ReadRequest (BusTypes.ReadRequest (baseAddr + offset) SizeByte) addr
+  LH    (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+    in Execute.ReadRequest (BusTypes.ReadRequest (baseAddr + offset) SizeHalfWord) addr
+  LW    (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+    in Execute.ReadRequest (BusTypes.ReadRequest (baseAddr + offset) SizeFullWord) addr
+  LBU   (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+    in Execute.ReadRequest (BusTypes.ReadRequest (baseAddr + offset) SizeByte) addr
+  LHU   (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+    in Execute.ReadRequest (BusTypes.ReadRequest (baseAddr + offset) SizeHalfWord) addr
+  JALR  (ITypeFields rd _ rs1 imm) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm
+        target = baseAddr + offset
+    in if rd /= 0 then WriteBackGPR rd (addr + 4) else Jump target
+  ECALL (ITypeFields _ _ _ _) ->
+    Execute.DecodeException EnvironmentCallFromMMode addr  -- Assuming Machine mode for now
+  EBREAK (ITypeFields _ _ _ _) ->
+    Execute.DecodeException Breakpoint addr
+
+  -- S-Type Instructions
+  SB (STypeFields _ rs1 rs2 imm12) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm12
+        val = extractRegVal rs2
+    in Execute.WriteRequest (BusTypes.WriteRequest (baseAddr + offset) (BusByte (resize val))) addr
+  SH (STypeFields _ rs1 rs2 imm12) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm12
+        val = extractRegVal rs2
+    in Execute.WriteRequest (BusTypes.WriteRequest (baseAddr + offset) (BusHalfWord (resize val))) addr
+  SW (STypeFields _ rs1 rs2 imm12) ->
+    let baseAddr = extractRegVal rs1
+        offset = signExtend imm12
+        val = extractRegVal rs2
+    in Execute.WriteRequest (BusTypes.WriteRequest (baseAddr + offset) (BusFullWord (resize val))) addr
+
+  -- B-Type Instructions
+  BEQ (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+        offset = signExtend imm13
+    in if val1 == val2 then Jump (addr + offset) else Jump (addr + 4)
+  BNE (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+        offset = signExtend imm13
+    in if val1 /= val2 then Jump (addr + offset) else Jump (addr + 4)
+  BLT (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        val2 = unpack (pack (extractRegVal rs2) :: BitVector 64) :: Signed 64
+        offset = signExtend imm13
+    in if val1 < val2 then Jump (addr + offset) else Jump (addr + 4)
+  BGE (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = unpack (pack (extractRegVal rs1) :: BitVector 64) :: Signed 64
+        val2 = unpack (pack (extractRegVal rs2) :: BitVector 64) :: Signed 64
+        offset = signExtend imm13
+    in if val1 >= val2 then Jump (addr + offset) else Jump (addr + 4)
+  BLTU (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+        offset = signExtend imm13
+    in if val1 < val2 then Jump (addr + offset) else Jump (addr + 4)
+  BGEU (BTypeFields _ rs1 rs2 imm13) ->
+    let val1 = extractRegVal rs1
+        val2 = extractRegVal rs2
+        offset = signExtend imm13
+    in if val1 >= val2 then Jump (addr + offset) else Jump (addr + 4)
+
+  -- U-Type Instructions
+  LUI (UTypeFields rd imm20) ->
+    let val = shiftL (resize imm20) 12
+    in WriteBackGPR rd val
+  AUIPC (UTypeFields rd imm20) ->
+    let val = addr + shiftL (resize imm20) 12
+    in WriteBackGPR rd val
+
+  -- J-Type Instructions
+  JAL (JTypeFields rd imm21) ->
+    let offset = signExtend imm21
+    in if rd /= 0 then WriteBackGPR rd (addr + 4) else Jump (addr + offset)
+
+execute (Decode.DecodeException e addr) = Execute.DecodeException e addr
+execute (Decode.InstructionException e addr) = Execute.InstructionException e addr
\ No newline at end of file