Package mars.mips.hardware

Class RegisterFile

java.lang.Object
mars.mips.hardware.RegisterFile
public class RegisterFile extends Object
Represents the collection of MIPS registers.
Version:
June 2003
Author:
Jason Bumgarner, Jason Shrewsbury

  • Field Details

    • GLOBAL_POINTER_REGISTER

      public static final int GLOBAL_POINTER_REGISTER
      See Also:
      Constant Field Values

    • STACK_POINTER_REGISTER

      public static final int STACK_POINTER_REGISTER
      See Also:
      Constant Field Values

  • Constructor Details

    • RegisterFile

      public RegisterFile()

  • Method Details

    • showRegisters

      public static void showRegisters()
      Display the register values for debugging.

    • updateRegister

      public static int updateRegister​(int num, int val)
      This method updates the register value whose number is num. Also handles the lo and hi registers
      Parameters:
      num - Register to set the value of.
      val - The desired value for the register.

    • updateRegister

      public static void updateRegister​(String reg, int val)
      Sets the value of the register given to the value given.
      Parameters:
      reg - Name of register to set the value of.
      val - The desired value for the register.

    • getValue

      public static int getValue​(int num)
      Returns the value of the register whose number is num.
      Parameters:
      num - The register number.
      Returns:
      The value of the given register.

    • getNumber

      public static int getNumber​(String n)
      For getting the number representation of the register.
      Parameters:
      n - The string formatted register name to look for.
      Returns:
      The number of the register represented by the string or -1 if no match.

    • getRegisters

      public static Register[] getRegisters()
      For returning the set of registers.
      Returns:
      The set of registers.

    • getUserRegister

      public static Register getUserRegister​(String regName)
      Get register object corresponding to given name. If no match, return null.
      Parameters:
      regName - The register name, either in $0 or $zero format.
      Returns:
      The register object,or null if not found.

    • initializeProgramCounter

      public static void initializeProgramCounter​(int value)
      For initializing the Program Counter. Do not use this to implement jumps and branches, as it will NOT record a backstep entry with the restore value. If you need backstepping capability, use setProgramCounter instead.
      Parameters:
      value - The value to set the Program Counter to.

    • initializeProgramCounter

      public static void initializeProgramCounter​(boolean startAtMain)
      Will initialize the Program Counter to either the default reset value, or the address associated with source program global label "main", if it exists as a text segment label and the global setting is set.
      Parameters:
      startAtMain - If true, will set program counter to address of statement labeled 'main' (or other defined start label) if defined. If not defined, or if parameter false, will set program counter to default reset value.

    • setProgramCounter

      public static int setProgramCounter​(int value)
      For setting the Program Counter. Note that ordinary PC update should be done using incrementPC() method. Use this only when processing jumps and branches.
      Parameters:
      value - The value to set the Program Counter to.
      Returns:
      previous PC value

    • getProgramCounter

      public static int getProgramCounter()
      For returning the program counters value.
      Returns:
      The program counters value as an int.

    • getProgramCounterRegister

      public static Register getProgramCounterRegister()
      Returns Register object for program counter. Use with caution.
      Returns:
      program counter's Register object.

    • getInitialProgramCounter

      public static int getInitialProgramCounter()
      For returning the program counter's initial (reset) value.
      Returns:
      The program counter's initial value

    • resetRegisters

      public static void resetRegisters()
      Method to reinitialize the values of the registers. NOTE: Should not be called from command-mode MARS because this this method uses global settings from the registry. Command-mode must operate using only the command switches, not registry settings. It can be called from tools running stand-alone, and this is done in AbstractMarsToolAndApplication.

    • incrementPC

      public static void incrementPC()
      Method to increment the Program counter in the general case (not a jump or branch).

    • addRegistersObserver

      public static void addRegistersObserver​(Observer observer)
      Each individual register is a separate object and Observable. This handy method will add the given Observer to each one. Currently does not apply to Program Counter.

    • deleteRegistersObserver

      public static void deleteRegistersObserver​(Observer observer)
      Each individual register is a separate object and Observable. This handy method will delete the given Observer from each one. Currently does not apply to Program Counter.