sim
Class BlockDevice

java.lang.Object
  |
  +--sim.BlockDevice

All Implemented Interfaces:

Memory

class BlockDevice

extends java.lang.Object

implements Memory

Implements a block device. Provides three registers:

1. 0: Block Address (device source or destination)
2. 4: Memory Address (memory source or destination)
3. 8: Control (bit0 = ready, bit1 = interrupt enable, bit2 = write bit3 = read). The ready bit is on when the device is ready to read or write more data. If bit1 is on, an interrupt will be delivered when the device completes its current operation. To initiate a write, bit2 is strobed; a read bit3 is strobed.

Field Summary

(package private) int	base
(package private) int	blockAddr
(package private) int	blockSize
(package private) int	ctl
(package private) java.io.RandomAccessFile	file
(package private) Mips	machine
(package private) int	memAddr

Constructor Summary

BlockDevice(Mips machine, java.io.RandomAccessFile file, int address, int blockSize)
Make a new block device connected to the given machine, at the given address, of the given block transfer size.

Method Summary

void	doCycle()
int	getSize()
void	initialize()
byte	readByte(int address)
int	readWord(int address)
java.lang.String	toString()
void	writeByte(int address, byte value)
void	writeWord(int address, int value)

Methods inherited from class java.lang.Object

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

Field Detail

file

java.io.RandomAccessFile file

machine

Mips machine

base

int base

blockAddr

int blockAddr

memAddr

int memAddr

blockSize

int blockSize

ctl

int ctl

Constructor Detail

BlockDevice

public BlockDevice(Mips machine,
                   java.io.RandomAccessFile file,
                   int address,
                   int blockSize)

Make a new block device connected to the given machine, at the given address, of the given block transfer size.

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getSize

public int getSize()

Specified by:

getSize in interface Memory

initialize

public void initialize()

Specified by:

initialize in interface Memory

doCycle

public void doCycle()

Specified by:

doCycle in interface Memory

readByte

public byte readByte(int address)

Specified by:

readByte in interface Memory

writeByte

public void writeByte(int address,
                      byte value)

Specified by:

writeByte in interface Memory

readWord

public int readWord(int address)

Specified by:

readWord in interface Memory

writeWord

public void writeWord(int address,
                      int value)

Specified by:

writeWord in interface Memory