byucc.jhdl.Xilinx.XC4000
Class bufgs

java.lang.Object
  byucc.jhdl.base.Nameable
      byucc.jhdl.base.Node
          byucc.jhdl.base.Cell
              byucc.jhdl.base.CL
                  byucc.jhdl.Xilinx.XC4000.bufgs

All Implemented Interfaces:

BooleanFlags, Buf, PreDefinedSchematic, byucc.jhdl.base.Propagateable, TreeListable, UnmappableCell

public final class bufgs

extends CL

implements UnmappableCell, Buf, PreDefinedSchematic

BUFGS, a secondary global buffer, distributes high fan-out clock or control signals throughout a PLD device. In CPLD designs, BUFGS is treated like BUFG. BUFGS provides direct access to Configurable Logic Block (CLB) clock pins and limited access to other CLB inputs. Four BUFGSs are available on each XC4000E and Spartan device, one in each corner. The input to a BUFGS comes either from a dedicated Input Output Block (IOB) or from an internal signal. Alongside each column of CLBs in an XC4000E or Spartan device are four global vertical lines, which are in addition to the standard vertical longlines. Each one of the four global vertical lines can drive the CLB clock (K) pin directly. In addition, one of the four lines can drive the F3 pin, a second line can drive the G1 pin, a third can drive the C3 pin, and a fourth can drive the C1 pin. Each of the four BUFGSs can drive any of these global vertical lines and are also used as the primary global buffers (refer also to the \"BUFGP\" section for more information). Because of its structure, a BUFGS can always access a clock pin directly. Because the BUFGS is more flexible than the BUFGP, it can use additional global vertical lines to access the F3, G1, C3, and C1 pins but requires multiple vertical lines in the same column. If the vertical lines in a given column are already used for BUFGPs or another BUFGS, PAR might have to feed signals through other CLBs to reach the load pins. To use a BUFGS in a schematic, connect the input of the BUFGS element either directly to the PAD symbol (for an external input) or to an internally sourced net. For an external signal, do not use any IBUFs, because the signal comes directly from the dedicated IOB. The output of the BUFGS is then used throughout the schematic. For a negative-edge clock, insert an INV (inverter) element between the output of the BUFGS and the clock input. This inversion is performed inside each CLB or IOB. The dedicated inputs for BUFGSs are identified by the names SGCK1 through SGCK4 in pinouts in XC4000E and Spartan. The package pin that drives the BUFGS depends on which corner the BUFGS is placed by PAR. (Source: XACT Libraries Guide, Chapter 3 BUFGS, Xilinx Corporation, 1999.)

Field Summary

static CellInterface[]	cell_interface The port interface for: bufgs i : in (1) o : out (1)
static java.lang.String	cellname The static cellname (netlist reference name) for bufgs

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.apps.Viewers.Schematic.PreDefinedSchematic

PreDefinedSchematic_ADD, PreDefinedSchematic_ADDSUB, PreDefinedSchematic_AND, PreDefinedSchematic_BUF, PreDefinedSchematic_CONST, PreDefinedSchematic_GEN, PreDefinedSchematic_GND, PreDefinedSchematic_INC, PreDefinedSchematic_INV, PreDefinedSchematic_MUX, PreDefinedSchematic_NAND, PreDefinedSchematic_NOR, PreDefinedSchematic_OR, PreDefinedSchematic_PULLDOWN, PreDefinedSchematic_PULLUP, PreDefinedSchematic_REG, PreDefinedSchematic_SHL, PreDefinedSchematic_SHR, PreDefinedSchematic_TBUF, PreDefinedSchematic_VCC, PreDefinedSchematic_XNOR, PreDefinedSchematic_XOR

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	bufgs(Node parent) Used only by child classes to pass up the parent cell.
	bufgs(Node parent, ArgBlockList abl) Constructs a new bufgs, connecting its ports as given by the String-Wire pairs in the ArgBlockList.
protected	bufgs(Node parent, java.lang.String name) Used only by child classes to pass up the parent cell and instance name.
	bufgs(Node parent, java.lang.String instanceName, ArgBlockList abl) Constructs a new bufgs, connecting its ports as given by the String-Wire pairs in the ArgBlockList.
	bufgs(Node parent, java.lang.String instanceName, java.lang.String s0, Wire w0, java.lang.String s1, Wire w1) Constructs a new bufgs, connecting each Wire to the port whose name is given by the accompanying String parameter The initial String parameter specifies the instance name.
	bufgs(Node parent, java.lang.String s0, Wire w0, java.lang.String s1, Wire w1) Constructs a new bufgs, connecting each Wire to the port whose name is given by the accompanying String parameter
	bufgs(Node parent, java.lang.String instanceName, Wire i, Wire o) Constructs a new bufgs.
	bufgs(Node parent, Wire i, Wire o) Constructs a new bufgs.

Method Summary

boolean	cellInterfaceDeterminesUniqueNetlistStructure() When false, the default behavior of this method, each cell will list itself separately in a netlist, guaranteeing that the netlist will not have invalid data at the expense of a larger file-size.
java.lang.String	getCellName() Access the cell name associated with a derived class.
static void	main(java.lang.String[] argv)
void	propagate() Used for things that are combinationally propagated like combinational logic and Wires and such.
static void	test()
int	type() This method returns one of the predefined schematic constants to identify the type of this cell.

Methods inherited from class byucc.jhdl.base.CL

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

Methods inherited from class byucc.jhdl.base.Cell

addPort, addPorts, addProperties, addProperties, addProperty, addProperty, addProperty, addProperty, antecedantIsBehaviorallyModeled, antecedantIsBehaviorallyModeled, bind, bind, bind, bind, clk, connect, connectAllWires, connectOptional, constructSubCell, constructSubCellNoImplicitPorts, disableAllBehavioralModels, disableBehavioralModel, enableBehavioralModel, getArgument, getAttachedPort, getAttachedWire, getAttachedWireNoException, 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

Field Detail

cellname

public static final java.lang.String cellname

The static cellname (netlist reference name) for bufgs

See Also:

Constant Field Values

cell_interface

public static CellInterface[] cell_interface

The port interface for: bufgs i : in (1) o : out (1)

Constructor Detail

bufgs

protected bufgs(Node parent)

Used only by child classes to pass up the parent cell.

Parameters:

parent - Parent cell

bufgs

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

Used only by child classes to pass up the parent cell and instance name.

Parameters:

parent - Parent cell

name - Instance name of the cell

bufgs

public bufgs(Node parent,
             Wire i,
             Wire o)

Constructs a new bufgs.

Parameters:

parent - The parent Cell to the bufgs

i - The Wire to be connected to input port i

o - The Wire to be connected to output port o

bufgs

public bufgs(Node parent,
             java.lang.String instanceName,
             Wire i,
             Wire o)

Constructs a new bufgs. The initial String parameter specifies the instance name.

Parameters:

parent - The parent Cell to the bufgs

instanceName - The instance name of the bufgs

i - The Wire to be connected to input port i

o - The Wire to be connected to output port o

bufgs

public bufgs(Node parent,
             java.lang.String s0,
             Wire w0,
             java.lang.String s1,
             Wire w1)

Constructs a new bufgs, connecting each Wire to the port whose name is given by the accompanying String parameter

Parameters:

parent - The parent Cell to the bufgs

s0 - The name of the port to which w0 will be connected

w0 - The Wire to be connected to the port specified by s0

s1 - The name of the port to which w1 will be connected

w1 - The Wire to be connected to the port specified by s1

bufgs

public bufgs(Node parent,
             java.lang.String instanceName,
             java.lang.String s0,
             Wire w0,
             java.lang.String s1,
             Wire w1)

Constructs a new bufgs, connecting each Wire to the port whose name is given by the accompanying String parameter The initial String parameter specifies the instance name.

Parameters:

parent - The parent Cell to the bufgs

instanceName - The instance name of the bufgs

s0 - The name of the port to which w0 will be connected

w0 - The Wire to be connected to the port specified by s0

s1 - The name of the port to which w1 will be connected

w1 - The Wire to be connected to the port specified by s1

bufgs

public bufgs(Node parent,
             ArgBlockList abl)

Constructs a new bufgs, connecting its ports as given by the String-Wire pairs in the ArgBlockList. Any generic assignments are made through String-String pairs in the ArgBlockList.

Parameters:

parent - The parent Cell to the bufgs

abl - The list of String-Wire pairs for port assignments, and String-String pairs for generic assignments.

bufgs

public bufgs(Node parent,
             java.lang.String instanceName,
             ArgBlockList abl)

Constructs a new bufgs, connecting its ports as given by the String-Wire pairs in the ArgBlockList. Any generic assignments are made through String-String pairs in the ArgBlockList. The initial String parameter is the instance name.

Parameters:

parent - The parent Cell to the bufgs

instanceName - The instance name of the bufgs

abl - The list of String-Wire pairs for port assignments, and String-String pairs for generic assignments.

Method Detail

getCellName

public java.lang.String getCellName()

Description copied from class: Cell

Access the cell name associated with a derived class. The cellname field is lazily evaluated on the first call of this method. Can be overriden to make cellname different by instance. If the field does not exist, this defaults to the classname.

Overrides:

getCellName in class Cell

Returns:

the cell name associated with a derived class, null if not declared.

cellInterfaceDeterminesUniqueNetlistStructure

public final boolean cellInterfaceDeterminesUniqueNetlistStructure()

Description copied from class: Cell

When false, the default behavior of this method, each cell will list itself separately in a netlist, guaranteeing that the netlist will not have invalid data at the expense of a larger file-size. Overriding this method to return true allows JHDL to save memory and netlists to be smaller by sharing the netlist structures that are guaranteed to be identical. NOTE: Do not override this unless every possible condition responsible for structural differences in a class (types and amount of children cells created, and arrangements of wires connected to ports) is included in the cellInterface[] of that class.

Overrides:

cellInterfaceDeterminesUniqueNetlistStructure in class Cell

Returns:

false if not overridden, preventing all memory sharing

propagate

public final void propagate()

Description copied from interface: byucc.jhdl.base.Propagateable

Used for things that are combinationally propagated like combinational logic and Wires and such.

Specified by:

propagate in interface byucc.jhdl.base.Propagateable

type

public int type()

Description copied from interface: PreDefinedSchematic

This method returns one of the predefined schematic constants to identify the type of this cell.

Specified by:

type in interface PreDefinedSchematic

Returns:

A predefined schematic constant

main

public static void main(java.lang.String[] argv)

test

public static void test()