nl.kbna.dioscuri.module.pit
Class Counter

java.lang.Object
  nl.kbna.dioscuri.module.pit.Counter

public class Counter
extends java.lang.Object

A single counter of the PIT based on the Intel 82C54 chipset. This counter works following the convention rules of the PIT: 1. For each counter, the control word must be written before the initial count is written. 2. The initial count must follow the count format specified in the Control Word (LSB, MSB, etc.)

Field Summary

protected boolean	bcd
private static boolean	BCD
private static boolean	BINARY
protected byte[]	ce
protected int	counterMode
private static int	COUNTERMODE_0
private static int	COUNTERMODE_1
private static int	COUNTERMODE_2
private static int	COUNTERMODE_3
private static int	COUNTERMODE_4
private static int	COUNTERMODE_5
private int	counterNumber
protected byte[]	cr
private static boolean	EVEN
private boolean	isEnabled
private boolean	isGateRising
private boolean	isLatched
private boolean	isTriggered
private static java.util.logging.Logger	logger
protected static int	LSB
private boolean	lsbRead
private boolean	lsbWritten
protected static int	MSB
private boolean	newCount
private static boolean	ODD
protected byte[]	ol
private boolean	parity
private PIT	pit
protected boolean	readBackCmd
protected int	rwMode
private static int	RWMODE_0
private static int	RWMODE_1
private static int	RWMODE_2
private static int	RWMODE_3
private boolean	signalClock
private boolean	signalGate
private boolean	signalOut

Constructor Summary

Counter(PIT pit, int counterNumber)
Constructor of the counter class

Method Summary

void	clockPulse() Performs counter action on one clockpulse.
protected boolean	getBCD() Return if this counter is in BCD mode
protected int	getCounterNumber() Return the counter number (ID)
protected byte	getCounterValue() Returns the counter value depending on the R/W mode
protected boolean	getGateSignal() Retrieves the GATE signal
protected boolean	getOutSignal() Retrieves the OUT signal
protected boolean	getParity() Return the parity of the count value
protected boolean	isEnabled() Return if this counter has been enabled
protected void	latchCounter() Latch this counter (read back current count value) Note: this function only works if the counter is in latchmode.
private void	loadCounter() Load counter with new value Note: new value is stored in register cr.
protected void	setCounterMode(int mode) Set counter mode
protected void	setCounterValue(byte data) Set counter value depending on the R/W mode Note: it is assumed that data is always loaded in LSB, MSB order.
protected void	setEnabled(boolean status) Enable/disable the counter
protected void	setGateSignal(boolean status) Sets the GATE signal to given status GATE signal is compared with its previous state.

Methods inherited from class java.lang.Object

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

Field Detail

pit

private PIT pit

counterNumber

private int counterNumber

signalClock

private boolean signalClock

signalGate

private boolean signalGate

signalOut

private boolean signalOut

counterMode

protected int counterMode

rwMode

protected int rwMode

bcd

protected boolean bcd

ce

protected byte[] ce

cr

protected byte[] cr

ol

protected byte[] ol

isEnabled

private boolean isEnabled

parity

private boolean parity

lsbWritten

private boolean lsbWritten

lsbRead

private boolean lsbRead

isLatched

private boolean isLatched

newCount

private boolean newCount

isTriggered

private boolean isTriggered

isGateRising

private boolean isGateRising

readBackCmd

protected boolean readBackCmd

logger

private static java.util.logging.Logger logger

LSB

protected static final int LSB

See Also:

Constant Field Values

MSB

protected static final int MSB

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Constant Field Values

ODD

private static final boolean ODD

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Constant Field Values

EVEN

private static final boolean EVEN

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Constant Field Values

BINARY

private static final boolean BINARY

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Constant Field Values

BCD

private static final boolean BCD

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Constant Field Values

RWMODE_0

private static final int RWMODE_0

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Constant Field Values

RWMODE_1

private static final int RWMODE_1

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Constant Field Values

RWMODE_2

private static final int RWMODE_2

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Constant Field Values

RWMODE_3

private static final int RWMODE_3

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Constant Field Values

COUNTERMODE_0

private static final int COUNTERMODE_0

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Constant Field Values

COUNTERMODE_1

private static final int COUNTERMODE_1

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Constant Field Values

COUNTERMODE_2

private static final int COUNTERMODE_2

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COUNTERMODE_3

private static final int COUNTERMODE_3

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COUNTERMODE_4

private static final int COUNTERMODE_4

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COUNTERMODE_5

private static final int COUNTERMODE_5

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Constant Field Values

Constructor Detail

Counter

public Counter(PIT pit,
               int counterNumber)

Constructor of the counter class

Method Detail

clockPulse

public void clockPulse()

Performs counter action on one clockpulse. The action depends on the mode the counter is set to, the GATE signal, R/W mode and BCD setting.

getGateSignal

protected boolean getGateSignal()

Retrieves the GATE signal

Returns:

boolean true if GATE is high, false if GATE is low

setGateSignal

protected void setGateSignal(boolean status)

Sets the GATE signal to given status GATE signal is compared with its previous state. If GATE is rising (low -> high), variable isGateRising is set to true If GATE is falling (high -> low), signal OUT is turned high immediately for some counter modes

Parameters:

boolean - status, containing the new value for GATE

getOutSignal

protected boolean getOutSignal()

Retrieves the OUT signal

Returns:

boolean true if OUT is high, false if OUT is low

getCounterValue

protected byte getCounterValue()

Returns the counter value depending on the R/W mode

Returns:

byte data containing the LSB/MSB from Counting Element (ce) or Output latch (ol)

setCounterValue

protected void setCounterValue(byte data)

Set counter value depending on the R/W mode Note: it is assumed that data is always loaded in LSB, MSB order. So, first LSB then MSB.

Parameters:

byte - data containing the LSB/MSB for counter

setCounterMode

protected void setCounterMode(int mode)

Set counter mode

Parameters:

int - mode ranging from 0 to 5

latchCounter

protected void latchCounter()

Latch this counter (read back current count value) Note: this function only works if the counter is in latchmode. The latched value is stored in register ol.

loadCounter

private void loadCounter()

Load counter with new value Note: new value is stored in register cr.

getParity

protected boolean getParity()

Return the parity of the count value

Returns:

boolean true=EVEN, false=ODD

getBCD

protected boolean getBCD()

Return if this counter is in BCD mode

Returns:

boolean true=BCD, false=decimal

setEnabled

protected void setEnabled(boolean status)

Enable/disable the counter

Parameters:

boolean - status defining the status of this counter (true=enabled, false=disabled)

isEnabled

protected boolean isEnabled()

Return if this counter has been enabled

Returns:

true if enabled, false otherwise

getCounterNumber

protected int getCounterNumber()

Return the counter number (ID)

Returns:

int counternumber