byucc.jhdl.base
Class PullUpDown

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

All Implemented Interfaces:

BooleanFlags, byucc.jhdl.base.Propagateable, TreeListable

Direct Known Subclasses:

keeper, keeper, pulldown, pulldown, pulldown, pulldown, pullup, pullup, pullup, pullup

public abstract class PullUpDown

extends CL

Author:

Brad L. Hutchings This implements a pullup or pulldown (as requested by the user) on a wire. The basic idea is that this element only propagates itself last and only if nobody else has sourced a value onto a wire. Necessary to implement tristate. They are only allowed to source a single wire (no fanout!).

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	PullUpDown(Node parent) Constructs an unnamed pullup or pulldown
protected	PullUpDown(Node parent, java.lang.String name) Constructs a named pullup or pulldown

Method Summary

Wire	connect(java.lang.String name, Wire w) Does some extra wire checking before calling the super method that actually does the work.
void	connectAllWires(ArgBlockList arg_list) Wires up all of the wires in the ArgBlockList to all of the named ports using the associations given them when they were put in the ArgBlockList.
abstract int	getOutputValue() Must be defined to be an integer value by the user.
boolean	isReadyToBeAsynchronouslyScheduled() pull-up/down cells can go on the list when all other sources for their output wire are already on the list.
void	propagate() PullUp/Down cells only propagate if nobody else has propagated to their output wire.

Methods inherited from class byucc.jhdl.base.CL

behavioralModelIsAvailable, defaultSimulationModelIsBehavioral, hasBeenTraced, hasBeenTraced, hasBehaviorInClockMethod, hasBehaviorInPropagateMethod, isAsynchronouslyScheduled, isAsynchronouslyScheduled, needsToBeAsynchronouslyScheduled

Methods inherited from class byucc.jhdl.base.Cell

addPort, addPorts, addProperties, addProperties, addProperty, addProperty, addProperty, addProperty, antecedantIsBehaviorallyModeled, antecedantIsBehaviorallyModeled, bind, bind, bind, bind, cellInterfaceDeterminesUniqueNetlistStructure, clk, 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, preorderCheck, 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, toString, 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

PullUpDown

protected PullUpDown(Node parent,
                     java.lang.String name)

Constructs a named pullup or pulldown

Parameters:

parent - the parent node

name - the pullup/down name

PullUpDown

protected PullUpDown(Node parent)

Constructs an unnamed pullup or pulldown

Parameters:

parent - the parent node

Method Detail

getOutputValue

public abstract int getOutputValue()

Must be defined to be an integer value by the user.

Returns:

the value that will be placed on the PullUp/Down's output wire.

connect

public final Wire connect(java.lang.String name,
                          Wire w)

Does some extra wire checking before calling the super method that actually does the work. You are only allowed to connect a single wire that is of atomic width.

Overrides:

connect in class Cell

Parameters:

name - the port to connect

w - the wire to connect

Returns:

the aliased wire that results from the connection

connectAllWires

public void connectAllWires(ArgBlockList arg_list)

Description copied from class: Cell

Wires up all of the wires in the ArgBlockList to all of the named ports using the associations given them when they were put in the ArgBlockList. Any non-wires are completely ignored and must be handled manually.

Overrides:

connectAllWires in class Cell

Parameters:

arg_list - all of the wire-port associations that need to be carried out. May also contain any other argument bindings to be handled manually by the user.

See Also:

ArgBlockList

isReadyToBeAsynchronouslyScheduled

public final boolean isReadyToBeAsynchronouslyScheduled()

pull-up/down cells can go on the list when all other sources for their output wire are already on the list.

Specified by:

isReadyToBeAsynchronouslyScheduled in interface byucc.jhdl.base.Propagateable

Overrides:

isReadyToBeAsynchronouslyScheduled in class CL

Returns:

true when ready to put on the list.

propagate

public final void propagate()

PullUp/Down cells only propagate if nobody else has propagated to their output wire.