diff --git a/src/emulate.c b/src/emulate.c
index fc508a0..631d1f0 100755
--- a/src/emulate.c
+++ b/src/emulate.c
@@ -1,3 +1,11 @@
+/** @file emulate.c
+ *  @brief The main file for the ARMv8 emulator. Reads a binary file and outputs
+ *  the state of the machine after executing the instructions in the file.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #include <stdlib.h>
 #include <stdio.h>
 #include "a64instruction/a64instruction.h"
@@ -20,6 +28,7 @@ int main(int argc, char **argv) {
     return EXIT_FAILURE;
   }
 
+  // If a second argument is provided, use it as output file instead of stdout.
   FILE *out = stdout;
   if (argc > 2) {
     out = fopen(argv[2], "w");
diff --git a/src/emulator/decode.c b/src/emulator/decode.c
index 39fde3b..569c63b 100644
--- a/src/emulator/decode.c
+++ b/src/emulator/decode.c
@@ -17,6 +17,102 @@
 // FIELDNAME_LSB and FIELDNAME_MSB, storing the result in the variable wrd
 #define getField(fieldname) getBits(wrd, fieldname##_LSB, fieldname##_MSB)
 
+/************************************
+ * CONSTANTS
+ ************************************/
+
+#define HALT_WORD 0x8a000000
+
+#define TYPE_ID_LSB 26
+#define TYPE_ID_MSB 29
+#define DP_IMM_ID 4
+#define BRANCH_ID 5
+
+#define DP_REG_FLAG_LSB 25
+#define DP_REG_FLAG_MSB 26
+
+#define DP_WIDTH_LSB 31
+#define DP_WIDTH_MSB 32
+#define DP_OP_LSB 29
+#define DP_OP_MSB 31
+#define DP_DEST_LSB 0
+#define DP_DEST_MSB 5
+
+#define DP_IMM_OPTYPE_LSB 23
+#define DP_IMM_OPTYPE_MSB 26
+#define DP_IMM_OPTYPE_ARITHM 2
+#define DP_IMM_OPTYPE_WIDEMOV 5
+#define DP_IMM_ARITHM_SHIFTFLAG_LSB 22
+#define DP_IMM_ARITHM_SHIFTFLAG_MSB 23
+#define DP_IMM_ARITHM_IMMVAL_LSB 10
+#define DP_IMM_ARITHM_IMMVAL_MSB 22
+#define DP_IMM_ARITHM_DEST_LSB 5
+#define DP_IMM_ARITHM_DEST_MSB 10
+#define DP_IMM_WIDEMOV_SHIFTSCALAR_LSB 21
+#define DP_IMM_WIDEMOV_SHIFTSCALAR_MSB 23
+#define DP_IMM_WIDEMOV_IMMVAL_LSB 5
+#define DP_IMM_WIDEMOV_IMMVAL_MSB 21
+
+#define DP_REG_SRC1_LSB 5
+#define DP_REG_SRC1_MSB 10
+#define DP_REG_SRC2_LSB 16
+#define DP_REG_SRC2_MSB 21
+#define DP_REG_OPTYPE_LSB 28
+#define DP_REG_OPTYPE_MSB 29
+#define DP_REG_ARITHMLOGIC_ARITHMFLAG_LSB 24
+#define DP_REG_ARITHMLOGIC_ARITHMFLAG_MSB 25
+#define DP_REG_ARITHMLOGIC_SHIFTTYPE_LSB 22
+#define DP_REG_ARITHMLOGIC_SHIFTTYPE_MSB 24
+#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_LSB 21
+#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_MSB 22
+#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_LSB 10
+#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_MSB 16
+#define DP_REG_MULTIPLY_SUMMAND_LSB 10
+#define DP_REG_MULTIPLY_SUMMAND_MSB 15
+#define DP_REG_MULTIPLY_NEGPROD_LSB 15
+#define DP_REG_MULTIPLY_NEGPROD_MSB 16
+#define DP_REG_MULTIPLY_PROCESSOP 0
+#define DP_REG_MULTIPLY_ARITHMFLAG 1
+#define DP_REG_MULTIPLY_SHIFTTYPE 0
+#define DP_REG_MULTIPLY_NEGSRC2FLAG 0
+
+#define SDT_OPTYPE_FLAG_LSB 31
+#define SDT_OPTYPE_FLAG_MSB 32
+#define SDT_REGTYPE_FLAG_LSB 30
+#define SDT_REGTYPE_FLAG_MSB 31
+#define SDT_TARGET_REG_LSB 0
+#define SDT_TARGET_REG_MSB 5
+
+#define SDT_BASE_REG_LSB 5
+#define SDT_BASE_REG_MSB 10
+#define SDT_OFFSET_LSB 10
+#define SDT_OFFSET_MSB 22
+#define SDT_TRANSFER_TYPE_LSB 22
+#define SDT_TRANSFER_TYPE_MSB 23
+#define SDT_UNSIGNED_FLAG_LSB 24
+#define SDT_UNSIGNED_FLAG_MSB 25
+#define SDT_REGISTER_FLAG_LSB 21
+#define SDT_REGISTER_FLAG_MSB 22
+#define SDT_REGISTER_REG_LSB 16
+#define SDT_REGISTER_REG_MSB 21
+#define SDT_INDEXED_ADDRMODE_LSB 11
+#define SDT_INDEXED_ADDRMODE_MSB 12
+#define SDT_INDEXED_OFFSET_LSB 12
+#define SDT_INDEXED_OFFSET_MSB 21
+#define SDT_LOAD_LITERAL_OFFSET_LSB 5
+#define SDT_LOAD_LITERAL_OFFSET_MSB 24
+
+#define BRANCH_TYPE_LSB 30
+#define BRANCH_TYPE_MSB 32
+#define BRANCH_UNCONDITIONAL_OFFSET_LSB 0
+#define BRANCH_UNCONDITIONAL_OFFSET_MSB 26
+#define BRANCH_REGISTER_SRC_LSB 5
+#define BRANCH_REGISTER_SRC_MSB 10
+#define BRANCH_CONDITIONAL_COND_LSB 0
+#define BRANCH_CONDITIONAL_COND_MSB 4
+#define BRANCH_CONDITIONAL_OFFSET_LSB 5
+#define BRANCH_CONDITIONAL_OFFSET_MSB 24
+
 /************************************
  * PROTOTYPES
  ************************************/
@@ -26,12 +122,10 @@ static void decodeBranch(word wrd, a64inst_instruction *inst);
 static void decodeDPRegister(word wrd, a64inst_instruction *inst);
 static void decodeSingleTransfer(word wrd, a64inst_instruction *inst);
 
-/** @brief The main decode function. Takes a word (uint32_t) representing the 
- *         instruction and decodes it into an a64inst_instruction struct.
- *  @param wrd The word (uint32_t) to be decoded in binary.
- *  @return a pointer to the heap-allocated a64inst_instruction struct 
- *          representing the decoded instruction if successful.
- */
+/************************************
+ * FUNCTIONS
+ ************************************/
+
 a64inst_instruction *decode(word wrd) {
 
     a64inst_instruction *inst = malloc(sizeof(a64inst_instruction));
diff --git a/src/emulator/decode.h b/src/emulator/decode.h
index 668e06e..964e5fc 100644
--- a/src/emulator/decode.h
+++ b/src/emulator/decode.h
@@ -1,96 +1,21 @@
+/** @file decode.h
+ *  @brief Decode Function from binary words to a special internal 
+ *  representation of instructions, a64inst_instruction.
+ *
+ *  This defines the decode function which takes a binary word (uint32_t) and
+ *  decodes it into an a64inst_instruction conveying the same information.
+ *  
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #include "../global.h"
 #include "../a64instruction/a64instruction.h"
 
-#define HALT_WORD 0x8a000000
-
-#define TYPE_ID_LSB 26
-#define TYPE_ID_MSB 29
-#define DP_IMM_ID 4
-#define BRANCH_ID 5
-
-#define DP_REG_FLAG_LSB 25
-#define DP_REG_FLAG_MSB 26
-
-#define DP_WIDTH_LSB 31
-#define DP_WIDTH_MSB 32
-#define DP_OP_LSB 29
-#define DP_OP_MSB 31
-#define DP_DEST_LSB 0
-#define DP_DEST_MSB 5
-
-#define DP_IMM_OPTYPE_LSB 23
-#define DP_IMM_OPTYPE_MSB 26
-#define DP_IMM_OPTYPE_ARITHM 2
-#define DP_IMM_OPTYPE_WIDEMOV 5
-#define DP_IMM_ARITHM_SHIFTFLAG_LSB 22
-#define DP_IMM_ARITHM_SHIFTFLAG_MSB 23
-#define DP_IMM_ARITHM_IMMVAL_LSB 10
-#define DP_IMM_ARITHM_IMMVAL_MSB 22
-#define DP_IMM_ARITHM_DEST_LSB 5
-#define DP_IMM_ARITHM_DEST_MSB 10
-#define DP_IMM_WIDEMOV_SHIFTSCALAR_LSB 21
-#define DP_IMM_WIDEMOV_SHIFTSCALAR_MSB 23
-#define DP_IMM_WIDEMOV_IMMVAL_LSB 5
-#define DP_IMM_WIDEMOV_IMMVAL_MSB 21
-
-#define DP_REG_SRC1_LSB 5
-#define DP_REG_SRC1_MSB 10
-#define DP_REG_SRC2_LSB 16
-#define DP_REG_SRC2_MSB 21
-#define DP_REG_OPTYPE_LSB 28
-#define DP_REG_OPTYPE_MSB 29
-#define DP_REG_ARITHMLOGIC_ARITHMFLAG_LSB 24
-#define DP_REG_ARITHMLOGIC_ARITHMFLAG_MSB 25
-#define DP_REG_ARITHMLOGIC_SHIFTTYPE_LSB 22
-#define DP_REG_ARITHMLOGIC_SHIFTTYPE_MSB 24
-#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_LSB 21
-#define DP_REG_ARITHMLOGIC_NEGSRC2FLAG_MSB 22
-#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_LSB 10
-#define DP_REG_ARITHMLOGIC_SHIFTAMOUNT_MSB 16
-#define DP_REG_MULTIPLY_SUMMAND_LSB 10
-#define DP_REG_MULTIPLY_SUMMAND_MSB 15
-#define DP_REG_MULTIPLY_NEGPROD_LSB 15
-#define DP_REG_MULTIPLY_NEGPROD_MSB 16
-// Defines the values for fields used for arithmetic/logic DPR instructions
-// that are necessary to indicate a multiplication instruction
-#define DP_REG_MULTIPLY_PROCESSOP 0
-#define DP_REG_MULTIPLY_ARITHMFLAG 1
-#define DP_REG_MULTIPLY_SHIFTTYPE 0
-#define DP_REG_MULTIPLY_NEGSRC2FLAG 0
-
-#define SDT_OPTYPE_FLAG_LSB 31
-#define SDT_OPTYPE_FLAG_MSB 32
-#define SDT_REGTYPE_FLAG_LSB 30
-#define SDT_REGTYPE_FLAG_MSB 31
-#define SDT_TARGET_REG_LSB 0
-#define SDT_TARGET_REG_MSB 5
-
-#define SDT_BASE_REG_LSB 5
-#define SDT_BASE_REG_MSB 10
-#define SDT_OFFSET_LSB 10
-#define SDT_OFFSET_MSB 22
-#define SDT_TRANSFER_TYPE_LSB 22
-#define SDT_TRANSFER_TYPE_MSB 23
-#define SDT_UNSIGNED_FLAG_LSB 24
-#define SDT_UNSIGNED_FLAG_MSB 25
-#define SDT_REGISTER_FLAG_LSB 21
-#define SDT_REGISTER_FLAG_MSB 22
-#define SDT_REGISTER_REG_LSB 16
-#define SDT_REGISTER_REG_MSB 21
-#define SDT_INDEXED_ADDRMODE_LSB 11
-#define SDT_INDEXED_ADDRMODE_MSB 12
-#define SDT_INDEXED_OFFSET_LSB 12
-#define SDT_INDEXED_OFFSET_MSB 21
-#define SDT_LOAD_LITERAL_OFFSET_LSB 5
-#define SDT_LOAD_LITERAL_OFFSET_MSB 24
-
-#define BRANCH_TYPE_LSB 30
-#define BRANCH_TYPE_MSB 32
-#define BRANCH_UNCONDITIONAL_OFFSET_LSB 0
-#define BRANCH_UNCONDITIONAL_OFFSET_MSB 26
-#define BRANCH_REGISTER_SRC_LSB 5
-#define BRANCH_REGISTER_SRC_MSB 10
-#define BRANCH_CONDITIONAL_COND_LSB 0
-#define BRANCH_CONDITIONAL_COND_MSB 4
-#define BRANCH_CONDITIONAL_OFFSET_LSB 5
-#define BRANCH_CONDITIONAL_OFFSET_MSB 24
+/** @brief The main decode function. Takes a word (uint32_t) representing the 
+ *         instruction and decodes it into an a64inst_instruction struct.
+ *  @param wrd The word (uint32_t) to be decoded in binary.
+ *  @return a pointer to the heap-allocated a64inst_instruction struct 
+ *          representing the decoded instruction if successful.
+ */
+a64inst_instruction *decode(word wrd);
diff --git a/src/emulator/emulator.h b/src/emulator/emulator.h
index 69d1408..33a92b0 100644
--- a/src/emulator/emulator.h
+++ b/src/emulator/emulator.h
@@ -1,3 +1,11 @@
+/** @file emulator.h
+ *  @brief Structures to represent the state of the ARMv8 machine to be used
+ *  in the emulator.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #ifndef __EMULATOR__
 #define __EMULATOR__
 #include "../global.h"
diff --git a/src/emulator/execute.c b/src/emulator/execute.c
index b1a6663..2ac3316 100644
--- a/src/emulator/execute.c
+++ b/src/emulator/execute.c
@@ -1,3 +1,14 @@
+/** @file execute.c
+ *  @brief Implementation of the execute function for the ARMv8 emulator.
+ * 
+ *  This defines the execute function which takes a pointer to the machine state
+ *  and a pointer to an a64inst_instruction struct and executes the instruction
+ *  updating the machine state accordingly.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #include <stdlib.h>
 #include <assert.h>
 #include "execute.h"
@@ -40,7 +51,7 @@ const executeFunction EXECUTE_FUNCTIONS[] =
      &executeBranch,
      &executeHalt};
 
-// Main execute function
+
 void execute(Machine *state, a64inst_instruction *inst) {
     EXECUTE_FUNCTIONS[inst->type](state, inst);
 }
diff --git a/src/emulator/execute.h b/src/emulator/execute.h
index 3acc17b..f9aafec 100644
--- a/src/emulator/execute.h
+++ b/src/emulator/execute.h
@@ -3,5 +3,11 @@
 #include "../a64instruction/a64instruction.h"
 #include "emulator.h"
 
+/** @brief Executes the given instruction on the given machine state.
+ *  Updates the machine state to reflect the execution of the instruction.
+ *
+ *  @param state The machine state to execute the instruction on.
+ *  @param inst The instruction to execute.
+ */
 void execute(Machine *state, a64inst_instruction *inst);
 #endif
diff --git a/src/emulator/machine_util.c b/src/emulator/machine_util.c
index 3a27c89..7899114 100644
--- a/src/emulator/machine_util.c
+++ b/src/emulator/machine_util.c
@@ -1,4 +1,13 @@
-/** Machine Util */
+/** @file machine_util.c
+ *  @brief Implementation of utility functions for manipulating the machine state.
+ *
+ *  This defines utility functions for reading and writing memory and registers,
+ *  which are used by the emulator to execute instructions.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #include "assert.h"
 #include "machine_util.h"
 #include "../a64instruction/a64instruction_global.h"
@@ -6,7 +15,6 @@
 #include "emulator.h"
 #include "../util/binary_util.h"
 
-// Returns the dword starting at address. The value is truncated if regType is a 64-bit register.
 dword readMemory(byte *memory, uint32_t address, a64inst_regType regType) {
     dword result = 0;
     int bytesPerWord = (regType == a64inst_W ? WORD_BITS : DWORD_BITS) / BYTE_BITS - 1;
@@ -20,7 +28,6 @@ dword readMemory(byte *memory, uint32_t address, a64inst_regType regType) {
     return result;
 }
 
-// Store into memory starting at address the given dword.
 void storeMemory(byte *memory, uint32_t address, dword data) {
     int bytesPerDword = DWORD_BITS / BYTE_BITS - 1;
     for (int i = 0; i <= bytesPerDword; i++) {
@@ -28,9 +35,6 @@ void storeMemory(byte *memory, uint32_t address, dword data) {
     }
 }
 
-// Read from processor register, ensuring that a valid register specifier is given
-// and accounting for the case where the zero register is accessed. Truncate
-// the 32 most significant bits stored in the R register when reading W register.
 dword readRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType) {
     assert(reg <= REGISTER_COUNT);
     if (reg == ZERO_REGISTER) {
@@ -40,8 +44,6 @@ dword readRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType reg
     }
 }
 
-// Write to a processor register, ensuring that a valid register specifier is given
-// and truncating the value being written when it can't fit in the specified register
 void writeRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType, dword value) {
     assert(reg <= REGISTER_COUNT);
     if (reg != ZERO_REGISTER) {
diff --git a/src/emulator/machine_util.h b/src/emulator/machine_util.h
index 14306dc..047287e 100644
--- a/src/emulator/machine_util.h
+++ b/src/emulator/machine_util.h
@@ -1,16 +1,55 @@
+/** @file machine_util.h
+ *  @brief Utility functions for manipulating the machine state.
+ *
+ *  This defines utility functions for reading and writing memory and registers,
+ *  which are used by the emulator to execute instructions.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #ifndef __MACHINE_UTIL__
 #define __MACHINE_UTIL__
 #include "../global.h"
 #include "../a64instruction/a64instruction_global.h"
 #include "emulator.h"
 
-
+/** @brief Reads a (double) word from memory starting at the given address.
+ *  If regType is a64inst_W, the value is truncated to 32 bits.
+ *
+ *  @param memory The starting address byte-addressable memory block.
+ *  @param address The address to read from.
+ *  @param regType The register type to truncate the value to if necessary.
+ *  @return The (double) word read from memory.
+ */
 dword readMemory(byte *memory, uint32_t address, a64inst_regType regType);
 
+/** @brief Stores a double word into memory starting at the given address.
+ *
+ *  @param memory The starting address byte-addressable memory block.
+ *  @param address The address to store the data at.
+ *  @param data The double word to store.
+ */
 void storeMemory(byte *memory, uint32_t address, dword data);
 
+/** @brief Reads a register from the machine state.
+ *  If regType is a64inst_W, the value is truncated to 32 bits.
+ *
+ *  @param state The machine state to read the register from.
+ *  @param reg The register specifier to read.
+ *  @param regType The register type to truncate the value to if necessary.
+ *  @return The value stored in the register, truncated if necessary.
+ */
 dword readRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType);
 
+/** @brief Writes a value to a register in the machine state.
+ *  If regType is a64inst_W, the value is truncated to 32 bits.
+ *
+ *  @param state The machine state to write the register to.
+ *  @param reg The register specifier to write to.
+ *  @param regType The register type to truncate the value to if necessary.
+ *  @param value The value to write to the register.
+ */
 void writeRegister(Machine *state, a64inst_regSpecifier reg, a64inst_regType regType, dword value);
 
 #endif
diff --git a/src/emulator/print.c b/src/emulator/print.c
index 36c7632..978a74a 100644
--- a/src/emulator/print.c
+++ b/src/emulator/print.c
@@ -1,3 +1,14 @@
+/** @file print.c
+ *  @brief Implementation of functions to print the machine state.
+ *  
+ *  The function prints the current machine state, including the registers, 
+ *  memory and condition codes. This is used to print the final state machine
+ *  in the emulator after all instructions have been executed.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <inttypes.h>
@@ -8,13 +19,11 @@
 
 #define UNSET_CONDITION_CODE_CHAR '-'
 
-// Prints the current machine state into the provided stream
 void printState(Machine *state, FILE *stream) {
     printRegisters(state, stream);
     printMemory(state, stream);
 }
 
-// Prints the current machine registers into the provided stream
 void printRegisters(Machine *state, FILE *stream) {
     fprintf(stream, "Registers:\n");
     for (int i = 0; i < REGISTER_COUNT; i++) {
@@ -27,7 +36,6 @@ void printRegisters(Machine *state, FILE *stream) {
                                           state->conditionCodes.Overflow ? 'V' : UNSET_CONDITION_CODE_CHAR);
 }
 
-// Prints all non-zero memory locations into the provided stream
 void printMemory(Machine *state, FILE *stream) {
     fprintf(stream, "\nNon-zero memory:\n");
 
diff --git a/src/emulator/print.h b/src/emulator/print.h
index 35001d9..9d946fd 100644
--- a/src/emulator/print.h
+++ b/src/emulator/print.h
@@ -1,10 +1,48 @@
+/** @file print.h
+ *  @brief Functions to print the machine state, inc registers and memory.
+ *  
+ *  The function prints the current machine state, including the registers, 
+ *  memory and condition codes. This is used to print the final state machine
+ *  in the emulator after all instructions have been executed.
+ *
+ *  @author Saleh Bubshait
+ *  @author Themis Demetriades
+ */
+
 #ifndef __PRINT__
 #define __PRINT__
 #include <stdio.h>
 #include "emulator.h"
 
+/** @brief Prints the current machine state into the provided stream.
+ *
+ *  @param state The machine state to print.
+ *  @param stream The stream to print the state to.
+ *
+ *  @see printRegisters
+ *  @see printMemory
+ */
 void printState(Machine *state, FILE *stream);
+
+/** @brief Prints the current machine registers into the provided stream.
+ *  The registers are printed in the format "Xn = value" where n is the register
+ *  number and value is the value stored in the register, in hexadecimal. The
+ *  program counter (PC) and condition codes are also printed. SP is ignored.
+ *
+ *  @param state The machine state to print the registers of.
+ *  @param stream The stream to print the registers to.
+ */
 void printRegisters(Machine *state, FILE *stream);
+
+/** @brief Prints all non-zero memory locations into the provided stream.
+ *  The memory is printed in the format "0xaddress: data" where address is the
+ *  memory address and data is the data stored at that address, in hexadecimal.
+ *  Memory locations are printed 4 bytes at a time.
+ *  Note. Only non-zero memory locations are printed!
+ *
+ *  @param state The machine state to print the memory of.
+ *  @param stream The stream to print the memory to.
+ */
 void printMemory(Machine *state, FILE *stream);
 
 #endif