byucc.jhdl.Logic.Modules.FloatingPoint
Class toFloat

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.Logic.Modules.FloatingPoint.toFloat

All Implemented Interfaces:

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

public class toFloat

extends Logic

implements Pipelineable

Fixed-point to floating-point converter (or integer to floating-point).

General Description

The toFloat module converts a fixed-point or integer input wire to a floating-point output wire.

To learn about the floating-point format, see the FloatingPoint package summary.

Usage Examples

The toFloat module can also be instanced using static method calls in the FLOATINGPOINT class. If desired, however, the constructor calls may be made explicitly, as shown below.

First, you must import the Logic.Modules.FloatingPoint package:

import byucc.jhdl.Logic.Modules.FloatingPoint.*;

To instance a toFloat the following constructor would be used:

new toFloat (this, fixedWire, floatWire, fixedExponent, fixedIsSigned, floatExpWidth, pipelined, name);

For a more complete example, see examples/toFloatExample.java.

Known Issues

• When the input wire is the smallest representable negative two's complement number, the output is undefined. This is because a signed-magnitude representation cannot represent the smallest two's complement number without using an extra bit. All other input values will convert correctly. This issue only applies to signed mode.

  For example: 1000 (binary two's complement) = -8, but this takes five bits in signed-magnitude form (1_(sign) 1000_(magnitude)). All other four-bit two's complement representations fit in four bits in signed-magnitude form.

  Solution: If the lowest negative number must be handled, sign-extend the input by one bit.

Constructors

For all available constructors, see Constructor Summary or Constructor Detail.

Version:

$Revision: 1.14 $

Author:

Brent Nelson, Aaron Stewart

Field Summary

static CellInterface[]

cell_interface

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

toFloat(Node parent, Wire fixedWire, Wire floatWire, int fixedExponent, boolean fixedIsSigned, int floatExponentWidth, boolean pipelined)
Generates a fixed-to-float converter with a default instance name.

toFloat(Node parent, Wire fixedWire, Wire floatWire, int fixedExponent, boolean fixedIsSigned, int floatExponentWidth, boolean pipelined, java.lang.String instanceName)
Generates a fixed-to-float converter.

Method Summary

void	clock() Used by the simulator.
void	compute(BV fixedBV, int fixedExponent, FloatBV floatBV) Computes a bit-accurate result without timing information.
boolean	defaultSimulationModelIsBehavioral() Used by the simulator.
int	getLatency() Returns the latency of the design.
void	propagate() Used by the simulator.
void	reset() Used by the simulator.

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, cellInterfaceDeterminesUniqueNetlistStructure, clk, connect, connectAllWires, connectOptional, 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, 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

cell_interface

public static CellInterface[] cell_interface

Constructor Detail

toFloat

public toFloat(Node parent,
               Wire fixedWire,
               Wire floatWire,
               int fixedExponent,
               boolean fixedIsSigned,
               int floatExponentWidth,
               boolean pipelined)

Generates a fixed-to-float converter with a default instance name.

See toFloat(Node, Wire, Wire, int, boolean, int, boolean, String).

toFloat

public toFloat(Node parent,
               Wire fixedWire,
               Wire floatWire,
               int fixedExponent,
               boolean fixedIsSigned,
               int floatExponentWidth,
               boolean pipelined,
               java.lang.String instanceName)

Generates a fixed-to-float converter.

The input wire fixedWire holds the fixed-point or integer value to be converted. The input is treated as an integer with a fixed base-two exponent, so that the true value is fixedWire * 2fixedExponent The fixedIsSigned parameter tells whether the value is signed (two's complement) or unsigned.

The output wire is the converted floating-point result. The floatExponentWidth parameter specifies the number of bits used for the exponent.

Method Detail

getLatency

public int getLatency()

Returns the latency of the design.

Specified by:

getLatency in interface Pipelineable

Returns:

The number of clock cycles from the time valid inputs appear until the outputs appear. If the circuit is fully combinational, zero is returned.

reset

public void reset()

Used by the simulator. This is part of the behavioral model, for clocked logic.

Specified by:

reset in interface Clockable

Overrides:

reset in class Structural

clock

public void clock()

Used by the simulator. This is part of the behavioral model, for clocked logic.

Specified by:

clock in interface Clockable

Overrides:

clock in class Structural

propagate

public void propagate()

Used by the simulator. This is part of the behavioral model, for combinational logic.

Specified by:

propagate in interface byucc.jhdl.base.Propagateable

Overrides:

propagate in class Structural

defaultSimulationModelIsBehavioral

public boolean defaultSimulationModelIsBehavioral()

Used by the simulator. The default simulation model is behavioral.

Overrides:

defaultSimulationModelIsBehavioral in class Structural

Returns:

true if TestBench or leafCell, false otherwise.

compute

public void compute(BV fixedBV,
                    int fixedExponent,
                    FloatBV floatBV)

Computes a bit-accurate result without timing information.