machine
Class AbstractMainMemory.Port

java.lang.Object
  machine.AbstractMainMemory.Port

Enclosing class:

AbstractMainMemory

public class AbstractMainMemory.Port
extends Object

Memory's port for reading and writing. This is the interface the memory presents to the CPU.

Constructor Summary

AbstractMainMemory.Port(AbstractMainMemory.MMU mmu)

Method Summary

UnsignedByte[]	read(int address, int length) Read a sequence of bytes from memory using an aligned address.
int	readInteger(int address) Read a 4-byte integer from memory using an aligned address.
int	readIntegerUnaligned(int address) Read a 4-byte integer from memory using a possibly-unaligned address.
UnsignedByte[]	readUnaliged(int address, int length) Read a sequence of bytes from memory using a possibly-unaligned address.
void	write(int address, UnsignedByte[] value) Write a sequence of bytes to memory using an aligned address.
void	writeInteger(int address, int value) Write a 4-byte integer to memory using an aligned address.
void	writeIntegerUnaligned(int address, int value) Write a 4-byte integer to memory using a possibly-unaligned address.
void	writeUnaligned(int address, UnsignedByte[] value) Write a sequence of bytes to memory using a possibly-unaligned address.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractMainMemory.Port

public AbstractMainMemory.Port(AbstractMainMemory.MMU mmu)

Method Detail

read

public UnsignedByte[] read(int address,
                           int length)
                    throws AbstractMainMemory.InvalidAddressException

Read a sequence of bytes from memory using an aligned address.

Parameters:

address - address of first byte.

length - number of bytes.

Returns:

array of memory value of the specified bytes.

Throws:

InvalidMemoryException - if any address in the range address to address+length-1 is out of range or if address % length != 0 (i.e., address is not aligned to length).

AbstractMainMemory.InvalidAddressException

readUnaliged

public UnsignedByte[] readUnaliged(int address,
                                   int length)
                            throws AbstractMainMemory.InvalidAddressException

Read a sequence of bytes from memory using a possibly-unaligned address.

Parameters:

address - address of first byte.

length - number of bytes.

Returns:

array of memory value of the specified bytes.

Throws:

InvalidMemoryException - if any address in the range address to address+length-1 is out of range.

AbstractMainMemory.InvalidAddressException

readInteger

public int readInteger(int address)
                throws AbstractMainMemory.InvalidAddressException

Read a 4-byte integer from memory using an aligned address.

Parameters:

address - address of first byte.

Returns:

integer value of the specified bytes.

Throws:

InvalidMemoryException - if any address in the range address to address+3 is out of range or if address % 4 != 0 (i.e., address is not aligned to length).

AbstractMainMemory.InvalidAddressException

readIntegerUnaligned

public int readIntegerUnaligned(int address)
                         throws AbstractMainMemory.InvalidAddressException

Read a 4-byte integer from memory using a possibly-unaligned address.

Parameters:

address - address of first byte.

Returns:

integer value of the specified bytes.

Throws:

InvalidMemoryException - if any address in the range address to address+3 is out of range.

AbstractMainMemory.InvalidAddressException

write

public void write(int address,
                  UnsignedByte[] value)
           throws AbstractMainMemory.InvalidAddressException

Write a sequence of bytes to memory using an aligned address.

Parameters:

address - address of first byte.

value - array of bytes to write into memory.

Throws:

InvalidMemoryException - if any address in the range address to address+value.length-1 is out of range or if address % length != 0 (i.e., address is not aligned to length).

AbstractMainMemory.InvalidAddressException

writeUnaligned

public void writeUnaligned(int address,
                           UnsignedByte[] value)
                    throws AbstractMainMemory.InvalidAddressException

Write a sequence of bytes to memory using a possibly-unaligned address.

Parameters:

address - address of first byte.

value - array of bytes to write into memory.

Throws:

InvalidMemoryException - if any address in the range address to address+value.length-1 is out of range.

AbstractMainMemory.InvalidAddressException

writeInteger

public void writeInteger(int address,
                         int value)
                  throws AbstractMainMemory.InvalidAddressException

Write a 4-byte integer to memory using an aligned address.

Parameters:

address - address of first byte.

value - integer to write into memory.

Throws:

InvalidMemoryException - if any address in the range address to address+3 is out of range or if address % 4 != 0 (i.e., address is not aligned to length).

AbstractMainMemory.InvalidAddressException

writeIntegerUnaligned

public void writeIntegerUnaligned(int address,
                                  int value)
                           throws AbstractMainMemory.InvalidAddressException

Write a 4-byte integer to memory using a possibly-unaligned address.

Parameters:

address - address of first byte.

value - integer to write into memory.

Throws:

InvalidMemoryException - if any address in the range address to address+3 is out of range.

AbstractMainMemory.InvalidAddressException