uk.co.javagear
Class Registers

java.lang.Object
  uk.co.javagear.Registers

public final class Registers
extends java.lang.Object

Zilog Z80 CPU BC, DE, HL, IX, IY register pair emulation.

Version:

18th January 2003

Author:

Copyright (C) 2002-2003 Chris White

See Also:

"JavaGear Final Project Report"

Field Summary

private Flag	f Flag register.
private int	high The register pair's high byte.
private int	high2 The high byte of the second register of the pair.
private int	low The register pair's low byte.
private int	low2 The low byte of the second register of the pair.

Constructor Summary

Registers(Flag fl)
Register pair constructor.

Method Summary

void	adc(int value) ADC 16 BIT - Add with carry.
void	add(int value) ADD 16 BIT (Verified with ZEXALL).
void	clear() Clear register.
void	dec() Decrement register pair.
private int	dec8(int value) Used to decrement the high or low bytes of the register pair.
void	decH() Decrement high byte of pair.
void	decL() Decrement low byte of pair.
void	ex() Exchange register banks.
int	get() Get value of register pair.
int	getH() Get high byte of pair.
int	getL() Get low byte of pair.
void	inc() Increment register pair.
private int	inc8(int value) Used to increment the high or low bytes of the register pair.
void	incH() Increment high byte of pair.
void	incL() Increment low byte of pair.
void	sbc(int value) SBC 16 BIT - Subtract with carry.
void	set(int value) Set register pair.
void	setH(int value) Set high byte of register pair.
void	setL(int value) Set low byte of register pair.

Methods inherited from class java.lang.Object

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

Field Detail

high

private int high

The register pair's high byte.

low

private int low

The register pair's low byte.

high2

private int high2

The high byte of the second register of the pair.

low2

private int low2

The low byte of the second register of the pair.

f

private Flag f

Flag register.

Constructor Detail

Registers

public Registers(Flag fl)

Register pair constructor.

Parameters:

fl - pointer to flag register.

Method Detail

clear

public void clear()

Clear register.

get

public int get()

Get value of register pair.

Returns:

value stored in the register pair.

getH

public int getH()

Get high byte of pair.

Returns:

value of the register's high byte.

getL

public int getL()

Get low byte of pair.

Returns:

value of the register's low byte.

set

public void set(int value)

Set register pair.

Parameters:

value - the value to set the register to (0 - 0xFFFF).

setH

public void setH(int value)

Set high byte of register pair.

Parameters:

value - value to set the high byte of the register to (0 - 0xFF).

setL

public void setL(int value)

Set low byte of register pair.

Parameters:

value - value to set the low byte of the register to (0 - 0xFF).

inc

public void inc()

Increment register pair.

incL

public void incL()

Increment low byte of pair.

incH

public void incH()

Increment high byte of pair.

inc8

private int inc8(int value)

Used to increment the high or low bytes of the register pair.

Parameters:

value - the value of the register pair's byte.

Returns:

the byte's new value.

dec

public void dec()

Decrement register pair.

decL

public void decL()

Decrement low byte of pair.

decH

public void decH()

Decrement high byte of pair.

dec8

private int dec8(int value)

Used to decrement the high or low bytes of the register pair.

Parameters:

value - the value of the register pair's byte.

Returns:

the byte's new value.

ex

public void ex()

Exchange register banks.

add

public void add(int value)

ADD 16 BIT (Verified with ZEXALL).

Parameters:

value - value to add.

adc

public void adc(int value)

ADC 16 BIT - Add with carry.

Parameters:

value - value to add.

sbc

public void sbc(int value)

SBC 16 BIT - Subtract with carry.

Parameters:

value - value to subtract.