byucc.jhdl.contrib.modgen
Class Sub

java.lang.Object
  byucc.jhdl.base.Nameable
      byucc.jhdl.base.Node
          byucc.jhdl.base.Cell
              byucc.jhdl.base.Structural
                  byucc.jhdl.Logic.LogicGates
                      byucc.jhdl.Logic.LogicStatic
                          byucc.jhdl.Logic.Logic
                              byucc.jhdl.contrib.modgen.Sub

All Implemented Interfaces:

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

Deprecated. Use Logic sub call instead (Sub was deprecated since it is XC4000 specific).

public class Sub

extends Logic

General Description

Sub creates an subtraction unit with generic length operands. The subtraction unit can optionally be registered, have carry in, or have carry out. All of the cells are RLOCd for precise placement. Users can instruct the module generator to place the cells along even bit boundaries or odd.

Implementation

All Technologies

The inputs a,b and output s must be the same wordsize.
If a carry in signal is supplied, 0 = borrow, 1 = no carry.

Pipelining

Pipelining is enabled by setting the registered parameter true.

The registers in the pipe can be stalled using a clk_en signal. clk_en can be passed in null for a perpetually enabled design. An exception will be thrown if clk_en is present when the module is unregistered.

Xilinx XC4000

Selecting bit alignment

Xilinx 4k parts require a CLB to initialize the carry chain. ODD_ALIGNED Sub units perform the calculation of the first bit of the sum in this initialization CLB (odd numbered bits are calculated in the F-LUTS), while EVEN_ALIGNED Sub units only initialize the carry chain in the first CLB.

Calculating module size

To find the CLB count for an Sub unit, take the wordsize of the operands and divide by two and add one. If the unit is EVEN_ALIGNED, also add the remainder

Author:

Jeremy Anderson

Field Summary

static CellInterface[]	cell_interface Deprecated.
static java.lang.String	cellname Deprecated.
static int	EVEN_ALIGNED Deprecated. constants to determine placement information EVEN_ALIGNED subtracters begin the carry chain with a FORCE.
static int	ODD_ALIGNED Deprecated.

Fields inherited from class byucc.jhdl.Logic.Logic

ABOVE, ALIGN_BOTTOM, ALIGN_CENTER, ALIGN_LEFT, ALIGN_LSB, ALIGN_MSB, ALIGN_RIGHT, ALIGN_TOP, BELOW, DOWN, EAST_OF, LEFT_OF, MAX_PACK, NORTH_OF, ON, ONTOP, ONTOP_OF, RIGHT_OF, SOUTH_OF, TOLEFT, TORIGHT, UNCONSTRAINED, UP, WEST_OF

Fields inherited from class byucc.jhdl.Logic.LogicGates

tech_mapper

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

Sub(Node parent, int alignment, boolean registered, Wire clk_en, Wire cin, Wire a, Wire b, Wire s, Wire cout)
Deprecated. Use Logic sub call instead (Sub was deprecated since it is XC4000 specific).

Method Summary

boolean	cellInterfaceDeterminesUniqueNetlistStructure() Deprecated. 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.
void	clock() Deprecated. Users define synchronous behavior in this method using standard JHDL constructs.
static int[]	compute(int width, int cin, int a, int b) Deprecated. Compute implements the behavior of the Sub for behavioral modelling of the circuit
protected boolean	defaultSimulationModelIsBehavioral() Deprecated. The default simulation model is behavioral
java.lang.String	getCellName() Deprecated. Access the cell name associated with a derived class.
void	propagate() Deprecated. Users defined propagatable behavior using standard JHDL constructs.
void	reset() Deprecated. If you define a behavior, you must also define a reset method for resetting the synchonous part of your model.

Methods inherited from class byucc.jhdl.Logic.Logic

clockDriver, clockDriver, connect_implicit_ports, connectImplicitPorts, constructSubCell, constructSubCellNoImplicitPorts, enableNewPlacement, enableNewPlacement, extend, extend, getDefaultClock, getDefaultTechMapper, getGlobalClock, getSinkCell, getSourceCell, getSourceCell, getSourceLeaf, getSourcePlaceable, getSourcePlaceableLeaf, getSubCellClass, getTechMapHint, getTechMapHint, getTechMapper, growAndShiftl, lockChildPlacement, lsb, lsb, map, map, map, map, map, map, map, map, map, map, map, map, map, map, map, map, map, map, map, msb, msb, msbIndx, netlist, netlist, netlist, netlist, netlist, netlist, netlist, netlist, padClock_o, padClock_o, padClock_o, padClock, padClock, padClock, padIn_o, padIn_o, padIn_o, padIn, padIn, padIn, padInout_o, padInout_o, padInout_o, padInout, padInout, padInout, padOut_o, padOut_o, padOut_o, padOut, padOut, padOut, padOutT_o, padOutT_o, padOutT_o, padOutT, padOutT, padOutT, place, place, place, place, place, place, place, place, place, place, place, place, place, place, place, place, place, printTechMapHints, range, rotate, rotate, scale, scale, setBBox, setDefaultTechMapper, setFloorPlannerIsMaster, setTechMappingEnabled, setWandH, signExtend_o, signExtend, signExtend, sink, source, takeBot_o, takeBot, takeBot, takeBotSigned_o, takeBotSigned, takeTop_o, takeTop, takeTop, techmap, techMappingEnabled, translate, translate, zeroExtend_o, zeroExtend, zeroExtend, zeroExtendRight_o, zeroExtendRight

Methods inherited from class byucc.jhdl.Logic.LogicStatic

add_o, add_o, and_o, and_o, and, and, buf_o, buf_o, buf, buf, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant, constant, constant, constant, constant, constant, constant, constant, constant, constant, gnd_o, gnd_o, gnd, gnd, gnd, gnd, mux_o, mux, nc, nc, nc, nc, nc, nc, not_o, not_o, not, not, or_o, or_o, or, or, reg_o, reg, vcc_o, vcc_o, vcc, vcc, vcc, vcc, wire, wire, wire, wire, xnor_o, xnor_o, xnor, xor_o, xor

Methods inherited from class byucc.jhdl.Logic.LogicGates

add_o, add_o, add_o, add_o, add_o, add_o, add, add, add, add, addsub_o, addsub_o, addsub_o, addsub_o, addsub_o, addsub_o, addsub, addsub, addsub, addsub, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and_o, and, and, and, and, and, and, and, and, and, and, and, and, and, and, and, and, and, and, ashiftr_o, ashiftr, ashiftr, buf_o, buf_o, buf, buf, checkValueRepresentableInWidth, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat_o, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, concat, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant_o, constant, constant, constant, constant, constant, constant, constant, constant, constant, constant, gnd_o, gnd_o, gnd, gnd, gnd, gnd, mux_o, mux_o, mux_o, mux_o, mux_o, mux_o, mux, mux, mux, mux, mux, mux, name, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand_o, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nand, nc, nc, nc, nc, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor_o, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, nor, not_o, not_o, not, not, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or_o, or, or, or, or, or, or, or, or, or, or, or, or, or, or, or, or, or, or, pulldown, pulldown, pullup, pullup, reg_o, reg_o, reg_o, reg_o, reg, reg, reg, reg, regc_o, regc_o, regc_o, regc_o, regc, regc, regc, regc, regce_o, regce_o, regce_o, regce_o, regce, regce, regce, regce, regp_o, regp_o, regp_o, regp_o, regp, regp, regp, regp, regpe_o, regpe_o, regpe_o, regpe_o, regpe, regpe, regpe, regpe, regr_o, regr_o, regr_o, regr_o, regr, regr, regr, regr, regre_o, regre_o, regre_o, regre_o, regre, regre, regre, regre, regs_o, regs_o, regs_o, regs_o, regs, regs, regs, regs, regse_o, regse_o, regse_o, regse_o, regse, regse, regse, regse, shiftl_o, shiftl, shiftl, shiftr_o, shiftr, shiftr, sub_o, sub_o, sub_o, sub_o, sub_o, sub_o, sub, sub, sub, sub, tbuf_o, tbuf_o, tbuf, tbuf, vcc_o, vcc_o, vcc, vcc, vcc, vcc, wire, wire, wire, wire, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor_o, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xnor, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor_o, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor, xor

Methods inherited from class byucc.jhdl.base.Structural

behavioralModelIsAvailable, clockMethodIsDisabled, clockMethodIsDisabled, clockMethodIsEnabled, clockMethodIsEnabled, hasBeenTraced, hasBeenTraced, hasBehaviorInClockMethod, hasBehaviorInPropagateMethod, isAsynchronouslyScheduled, isAsynchronouslyScheduled, isFallingEdgeTriggered, isReadyToBeAsynchronouslyScheduled, isRisingEdgeTriggered, needsToBeAsynchronouslyScheduled, needsToBeClocked, propagateMethodIsDisabled, propagateMethodIsDisabled, propagateMethodIsEnabled, propagateMethodIsEnabled, willUseHWUpdate, willUseHWUpdate

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, 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, 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, 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

EVEN_ALIGNED

public static final int EVEN_ALIGNED

Deprecated.

constants to determine placement information EVEN_ALIGNED subtracters begin the carry chain with a FORCE. Even numbered bit subs occur on the bottom CLB boundary. ODD_ALIGNED subtracters perform the lsb sub in the bottom CLB. Odd numbered bit subs occur on the bottom CLB boundary.

See Also:

Constant Field Values

ODD_ALIGNED

public static final int ODD_ALIGNED

Deprecated.

See Also:

Constant Field Values

cell_interface

public static CellInterface[] cell_interface

Deprecated.

cellname

public static final java.lang.String cellname

Deprecated.

Constructor Detail

Sub

public Sub(Node parent,
           int alignment,
           boolean registered,
           Wire clk_en,
           Wire cin,
           Wire a,
           Wire b,
           Wire s,
           Wire cout)

Deprecated. Use Logic sub call instead (Sub was deprecated since it is XC4000 specific).

Constructor for Sub unit

Parameters:

parent - Parent of this circuit

alignment - EVEN_ALIGNED or ODD_ALIGNED

registered - True for output registers, false for no registers

clk_en - Clock enable wire

cin - Carry in wire. Null for no carry in.

a - A operand

b - B operand

s - Result wire.

cout - Carry out wire. Null for no carry out.

Method Detail

getCellName

public java.lang.String getCellName()

Deprecated.

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 boolean cellInterfaceDeterminesUniqueNetlistStructure()

Deprecated.

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

defaultSimulationModelIsBehavioral

protected boolean defaultSimulationModelIsBehavioral()

Deprecated.

The default simulation model is behavioral

Overrides:

defaultSimulationModelIsBehavioral in class Structural

Returns:

true if TestBench or leafCell, false otherwise.

compute

public static int[] compute(int width,
                            int cin,
                            int a,
                            int b)

Deprecated.

Compute implements the behavior of the Sub for behavioral modelling of the circuit

Parameters:

width - Wordsize of the Sub

cin - carry in to the Sub

a - a input.

b - b input.

Returns:

Array of integers containing the sum and carryout of the Sub

propagate

public void propagate()

Deprecated.

Description copied from class: Structural

Users defined propagatable behavior using standard JHDL constructs. The simulator detects whether propagate() has been implemented by calling function directly and checking for an exception.

Specified by:

propagate in interface byucc.jhdl.base.Propagateable

Overrides:

propagate in class Structural

clock

public void clock()

Deprecated.

Description copied from class: Structural

Users define synchronous behavior in this method using standard JHDL constructs. The simulator detects whether clock() has been implemented by calling this function directly and checking for an exception.

Specified by:

clock in interface Clockable

Overrides:

clock in class Structural

reset

public void reset()

Deprecated.

Description copied from class: Structural

If you define a behavior, you must also define a reset method for resetting the synchonous part of your model. If the user forgets to implement this, he will be reminded at simulation time.

Specified by:

reset in interface Clockable

Overrides:

reset in class Structural