byucc.jhdl.base
Class ClockDriver

java.lang.Object
  byucc.jhdl.base.Nameable
      byucc.jhdl.base.Node
          byucc.jhdl.base.Cell
              byucc.jhdl.base.CL
                  byucc.jhdl.base.ClockDriver

All Implemented Interfaces:

BooleanFlags, byucc.jhdl.base.Propagateable, TreeListable, UndrivenInputsAllowable

Direct Known Subclasses:

ClockDriver, CSRCClockDriver, DynamicClockDriver, XilinxClockDriver

public abstract class ClockDriver

extends CL

implements UndrivenInputsAllowable

Class used to create clock drivers. User's specify the schedule for the clock driver using a String of 1s and 0s.

Author:

Brad Hutchings

Field Summary

Fields inherited from class byucc.jhdl.base.Cell

BOOLEAN, CELL_NAME_DECLARATION, CellInterfaceDeterminesUniqueNetlistStructure, DETERMINE_FROM_STRING, GENERICS_DECLARATION, implicit_interface, IMPLICIT_INTERFACE_DECLARATION, INTEGER, INTERFACE_DECLARATION, LONG, PORT_IOS_DECLARATION, PORT_NAMES_DECLARATION, PORT_NET_NAMES_DECLARATION, PORT_PROPERTIES, PORT_WIDTHS_DECLARATION, SIGN_EXT, STRING, ZERO_PAD

Fields inherited from interface byucc.jhdl.base.BooleanFlags

ANTECEDANT_IS_BEHAVIORALLY_MODELED, ASYNC_PORT, ASYNCHRONOUS_RESOLVED, ATOMICALLY_PLACEABLE, ATOMICALLY_UNMAPPABLE, BEHAVIORALLY_MODELED_BRANCH, CLK_PORT, CLOCK_METHOD_IMPLEMENTED_BY_USER, CLOCK_METHOD_IS_DISABLED, CLOCKABLE_IS_SCHEDULED, DANGLING_IS_OK, DELETE_MARK, FATAL_BUILD_ERROR_OCCURED, HAS_BEEN_TRACED, HAS_USER_SPECIFIED_NAME, HWUPDATE, IMPLICIT_PORT, IN_CLK_PORT, IN_PORT, INOUT_PORT, IO_TYPE_FLAGS, IS_BEHAVIORALLY_MODELED, IS_ON_BUILD_STACK, IS_ON_PROP_LIST, IS_PLACED, METHODS_IMPLEMENTED_BY_USER, NETLISTABLE, ORIG_WIRE_IS_ATOMIC, OUT_PORT, PLACEMENT_IS_LOCKED, PROPAGATE_METHOD_IMPLEMENTED_BY_USER, PROPAGATE_METHOD_IS_DISABLED, RECURSION_FLAG, RESET_METHOD_IMPLEMENTED_BY_USER, SIMULATEABLE, SOURCELESS_IS_OK, SYNC_PORT, VISIBLE

Constructor Summary

protected	ClockDriver(Node parent, java.lang.String schedule, Wire clock) Main constructor for class.
protected	ClockDriver(Node parent, java.lang.String schedule, Wire clock, java.lang.String name) Main constructor for class.
protected	ClockDriver(Node parent, Wire clock) Alternate constructor for the class, which allows delayed determination of the schedule.
protected	ClockDriver(Node parent, Wire clock, java.lang.String name) Alternate constructor for the class, which allows delayed determination of the schedule.

Method Summary

protected java.lang.String	determineSchedule() If this clockDriver was constructed without a schedule, this method will be called just before simulation begins.
java.lang.String	getSchedule() Just returns the String representation of the clock driver schedule.
protected int	getScheduledValue(int schedule_index) Returns the integer value for the ClockDriver for that time index of its schedule.
boolean	needsToBeAsynchronouslyScheduled() Because this is currently a CL -- may change in the future (probably).
boolean	portMayBeUndriven(java.lang.String name) Returns true, as the clock driver never reads its input (if any exist, they are for netlisting only)
protected boolean	preorderCheck() Used to check validity of this ClockDriver before recursing down.
void	propagate() Does nothing, as clock drivers are scheduled directly by the simulator.
java.lang.String	toString() Provides a String describing this ClockDriver.

Methods inherited from class byucc.jhdl.base.CL

behavioralModelIsAvailable, defaultSimulationModelIsBehavioral, hasBeenTraced, hasBeenTraced, hasBehaviorInClockMethod, hasBehaviorInPropagateMethod, isAsynchronouslyScheduled, isAsynchronouslyScheduled, isReadyToBeAsynchronouslyScheduled

Methods inherited from class byucc.jhdl.base.Cell

addPort, addPorts, addProperties, addProperties, addProperty, addProperty, addProperty, addProperty, antecedantIsBehaviorallyModeled, antecedantIsBehaviorallyModeled, bind, bind, bind, bind, cellInterfaceDeterminesUniqueNetlistStructure, clk, connect, connectAllWires, connectOptional, constructSubCell, constructSubCellNoImplicitPorts, disableAllBehavioralModels, disableBehavioralModel, enableBehavioralModel, getArgument, getAttachedPort, getAttachedWire, getAttachedWireNoException, getCellName, getCellNetlist, getCellNetList, getCellNetlist, getCellNetlist, getDescendents, getFlatNetlist, getFlatNetlistableChildren, getGeneric, getHeight, getNetlistableChildren, getPlacementInfo, getPortProperties, getPortRecord, getPortRecords, getProperties, getProperty, getPropertyValue, getSinkWires, getSourceWires, getSubCellClass, getUniqueCellName, getWidth, getX, getY, hasPort, hasPorts, in, in, inout, inout, isAsynchronousSourceSinkResolved, isBehaviorallyModeled, isBehaviorallyModeledBranch, isInput, isLeafCell, isNetlistable, isNetlistable, isNetlistablePort, isNetlistLeaf, isNotNetlistable, isNotNetlistablePort, isNotVisible, isOutput, isPlaceable, isPlaceable, isPlaced, isPlaced, isPlacementLocked, isRoot, isSimulateable, isSimulateable, isSink, isSource, isVisible, isVisible, join, lockPlacement, nc, out, out, param, popHierarchy, port, port, port, postorderCheck, pushHierarchy, pushHierarchy, pushHierarchy, pushHierarchy, pushHierarchyNoImplicitPorts, pushHierarchyNoImplicitPorts, removeAllUnconnectedPorts, removePort, removeProperty, replaceProperty, replaceProperty, resetBehavioralModelsToDefaults, setAsynchronousSourceSinkResolved, setGeneric, setHeight, setNotNetlistable, setNotNetlistable, setNotVisible, setNotVisible, setPlacementInfo, setPortNotNetlistable, setPortNotNetlistable, setProperty, setWidth, subClassDelete, uniquifyCell, userDefinedClockCount, verifyAndCleanup

Methods inherited from class byucc.jhdl.base.Node

addObservable, addSimulatorCallback, checkAll, delete, getBuildingFlag, getChildren, getChildrenEnumeration, getDefaultClock, getInstanceName, getParent, getParentCell, getRelatives, getSystem, getWires, optimize, orphanAllowed, printAllChildren, printTree, removeSimulatorCallback, setDefaultClock

Methods inherited from class byucc.jhdl.base.Nameable

caseSensitivity, caseSensitivity, disableNameClashChecking, getFullName, getFullNameNoTestBench, getHierNameNoTestBench, getInstanceNo, getInstanceNumber, getLeafName, getLeafName, getRelativeName, getUserName, getUserName, hasUserSpecifiedName, isDescendantOf, setInstanceNumber

Methods inherited from class java.lang.Object

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

Constructor Detail

ClockDriver

protected ClockDriver(Node parent,
                      java.lang.String schedule,
                      Wire clock,
                      java.lang.String name)

Main constructor for class.

Parameters:

parent - the parent of the clock driver.

schedule - the String representation, e.g., "1010" of the schedule of the clock driver.

clock - the output clock wire of this driver.

name - the name of the clock driver.

ClockDriver

protected ClockDriver(Node parent,
                      Wire clock,
                      java.lang.String name)

Alternate constructor for the class, which allows delayed determination of the schedule. For example, in the Xilinx library, it is possible to create a secondary clkdll/bufg pair that derives its schedule from a primary one, such as when generating a 4x clock. Just before simulation, the method determineSchedule() will be called, and must return a clock schedule that is compatible with existing ones.

Parameters:

parent - the parent of the clock driver.

clock - the output clock wire of this driver.

name - the name of the clock driver.

ClockDriver

protected ClockDriver(Node parent,
                      java.lang.String schedule,
                      Wire clock)

Main constructor for class.

Parameters:

parent - the parent of the clock driver.

schedule - the String representation, e.g., "1010" of the schedule of the clock driver.

clock - the output clock wire of this driver.

ClockDriver

protected ClockDriver(Node parent,
                      Wire clock)

Alternate constructor for the class, which allows delayed determination of the schedule. For example, in the Xilinx library, it is possible to create a secondary clkdll/bufg pair that derives its schedule from a primary one, such as when generating a 4x clock. Just before simulation, the method determineSchedule() will be called, and must return a clock schedule that is compatible with existing ones.

Parameters:

parent - the parent of the clock driver.

clock - the output clock wire of this driver.

Method Detail

preorderCheck

protected boolean preorderCheck()

Used to check validity of this ClockDriver before recursing down. Extends Cell.preorderCheck() to include a check for a valid clock schedule. If this was created without a schedule, the method determineSchedule() will be called to generate the schedule.

Overrides:

preorderCheck in class Cell

Returns:

true if no errors occured, false otherwise.

Throws:

BuildException - if the clock schedule is invalid.

See Also:

Cell#checkAllNodes().

determineSchedule

protected java.lang.String determineSchedule()

If this clockDriver was constructed without a schedule, this method will be called just before simulation begins. At that time, the circuit should be finalized so that any querying of attached components will work. This method must be overridden to return a valid string; the implementation here returns null which is invalid. @return a valid clock schedule string

getScheduledValue

protected int getScheduledValue(int schedule_index)

Returns the integer value for the ClockDriver for that time index of its schedule.

Parameters:

schedule_index - indicates what point of the schedule you are interested in.

Returns:

the scheduled driver value for the provided index.

Throws:

BuildException - if this clockDriver does not yet have a schedule

getSchedule

public java.lang.String getSchedule()

Just returns the String representation of the clock driver schedule.

Returns:

the original user-specified clock driver schedule, or null if not yet specified.

needsToBeAsynchronouslyScheduled

public boolean needsToBeAsynchronouslyScheduled()

Because this is currently a CL -- may change in the future (probably).

Specified by:

needsToBeAsynchronouslyScheduled in interface byucc.jhdl.base.Propagateable

Overrides:

needsToBeAsynchronouslyScheduled in class CL

Returns:

true if it needs to be propagated, false otherwise.

toString

public java.lang.String toString()

Provides a String describing this ClockDriver.

Overrides:

toString in class Cell

Returns:

the description of this

propagate

public void propagate()

Does nothing, as clock drivers are scheduled directly by the simulator.

Specified by:

propagate in interface byucc.jhdl.base.Propagateable

portMayBeUndriven

public final boolean portMayBeUndriven(java.lang.String name)

Returns true, as the clock driver never reads its input (if any exist, they are for netlisting only)

Specified by:

portMayBeUndriven in interface UndrivenInputsAllowable

Parameters:

name - the name of the port to check (ignored)

Returns:

true, as undriven inputs are allowed