hwt.synthesizer.rtlLevel package

rtlLevel is responsible for RtlSignal manipulation and design.

Submodules

hwt.synthesizer.rtlLevel.exceptions module

exception hwt.synthesizer.rtlLevel.exceptions.SignalDriverErr

Bases: Exception

Signal has multiple combinational drivers (this is not possible in real word) or signal has no driver specified and it drives something which has effect on any output of component (it needs to have a driver but it does not have one)

Note:

SignalDriverErr([(SignalDriverErrType, sig), ])

class hwt.synthesizer.rtlLevel.exceptions.SignalDriverErrType(*values)

Bases: Enum

INPUT_WITH_DRIVER = 3

MISSING_DRIVER = 0

MULTIPLE_COMB_DRIVERS = 1

OUTPUT_WITHOUT_DRIVER = 2

hwt.synthesizer.rtlLevel.extract_part_drivers module

hwt.synthesizer.rtlLevel.fill_stm_list_with_enclosure module

class hwt.synthesizer.rtlLevel.fill_stm_list_with_enclosure.HdlAssignmentContainer_constructor(src, dst)

Bases: object

__init__(src, dst)

hwt.synthesizer.rtlLevel.fill_stm_list_with_enclosure.fill_stm_list_with_enclosure(parentStm: HdlStatement | None, current_enclosure: Set[RtlSignalBase], statements: ListOfHdlStatement, do_enclose_for: List[RtlSignalBase], enclosure: Dict[RtlSignalBase, Callable[[], HdlStatement]]) → ListOfHdlStatement

Apply enclosure on list of statements (fill all unused code branches with assignments from value specified by enclosure)

Parameters:

• parentStm – optional parent statement where this list is some branch

• current_enclosure – list of signals for which this statement list is enclosed

• statements – list of statements

• do_enclose_for – selected signals for which enclosure should be used

• enclosure – enclosure values for signals

Attention:

original statements parameter can be modified

Returns:

new statements

hwt.synthesizer.rtlLevel.mark_visibility_of_signals_and_check_drivers module

class hwt.synthesizer.rtlLevel.mark_visibility_of_signals_and_check_drivers.RtlNetlistPassMarkVisibilityOfSignalsAndCheckDrivers

Bases: RtlNetlistPass

runOnRtlNetlist(netlist: RtlNetlist)

• check if all signals are driven by something

• mark signals with hidden = False if they are connecting statements or if they are external interface

hwt.synthesizer.rtlLevel.mark_visibility_of_signals_and_check_drivers.walk_assignments(stm: HdlStatement, dst: RtlSignal) → Generator[HdlAssignmentContainer, None, None]

hwt.synthesizer.rtlLevel.netlist module

hwt.synthesizer.rtlLevel.reduce_processes module

hwt.synthesizer.rtlLevel.remove_unconnected_signals module

hwt.synthesizer.rtlLevel.rtlNetlistPass module

class hwt.synthesizer.rtlLevel.rtlNetlistPass.RtlNetlistPass

Bases: object

runOnRtlNetlist(netlist: RtlNetlist)

hwt.synthesizer.rtlLevel.rtlSignal module

class hwt.synthesizer.rtlLevel.rtlSignal.CREATE_NEXT_SIGNAL

Bases: object

__init__()

class hwt.synthesizer.rtlLevel.rtlSignal.RtlSignal(ctx: RtlNetlist, name: str, dtype: HdlType, def_val=None, nop_val=<class 'hwt.constants.NOT_SPECIFIED'>, next_signal: NOT_SPECIFIED'>, <class 'hwt.synthesizer.rtlLevel.rtlSignal.CREATE_NEXT_SIGNAL'>]=<class 'hwt.constants.NOT_SPECIFIED'>, virtual_only=False, is_const=False)

Bases: RtlSignalBase, HdlSignalItem

RtlSignal signal is a connection between statements and operators in circuit graph.

Variables:

• ~._rtlEndpoints – SetList of operators and statements for which this signal is driver.

• ~._rtlDrivers – SetList of operators and statements which can drive this signal. If driver is statement tree only top statement is present.

• ~._usedOps – A dictionary of used operators which can be reused.

• ~._usedOpsAlias – A dictionary tuple of operator and operands to set of tuples of operator and operands, used to resolve which combination of the operator and operands resulted in to same result.

• ~._isUnnamedExpr – means that this signal is part of expression and should not be rendered

• ~._nop_val – value which is used to fill up statements when no other value is assigned, use NOT_SPECIFIED to disable

• ~._const – flag which tell that this signal can not have any other driver than a default value

• __instCntr – counter used for generating instance ids

• ~._instId – internally used only for intuitive sorting of statements in serialized code

• ~._rtlObjectOrigin – optionally an object which generated this signal

• ~._rtlNextSig – optional signal signal which is used as a next signal if this RtlSignal is actually a FF output.

Note:

The _usedOps, _usedOpsAlias cache record is generated only for the left most signal in expression.

__init__(ctx: RtlNetlist, name: str, dtype: HdlType, def_val=None, nop_val=<class 'hwt.constants.NOT_SPECIFIED'>, next_signal: NOT_SPECIFIED'>, <class 'hwt.synthesizer.rtlLevel.rtlSignal.CREATE_NEXT_SIGNAL'>]=<class 'hwt.constants.NOT_SPECIFIED'>, virtual_only=False, is_const=False)

Parameters:

• ctx – context - RtlNetlist which is this signal part of

• name – name hint for this signal, if is None name is chosen automatically

• def_val – value which is used for reset and as default value in HDL

• nop_val – value which is used to fill up statements when no other value is assigned, use NOT_SPECIFIED to disable

• is_const – flag which tell that this signal can not have any other driver than a default value

_auto_cast(toType: HdlType)

Cast value or signal of this type to another compatible type.

Parameters:

toType – instance of HdlType to cast into

_const

_create_HOperator(operator: HOperatorDef, opCreateDelegate, *otherOps) → Self | HConst

Try lookup operator with this parameters in _usedOps if not found create new one and stored it in _usedOps

Parameters:

• operator – instance of HOperatorDef

• opCreateDelegate – function (*ops) to create operator

• otherOps – other operands (ops = self + otherOps)

Returns:

RtlSignal which is result of newly created operator

_ctx

_explicit_cast(toType: HdlType)

Cast value or signal of this type to another friendly type.

Parameters:

toType – instance of HdlType to cast into

_getAssociatedClk() → Self

_getAssociatedRst() → Self

_getDestinationSignalForAssignmentToThis()

Returns:

a signal which should be used as a destination if assigning to this signal

_getIndexCascade()

Find out if this signal is something indexed

_hasGenericName

_hdlName

_hwIO

_instId: int

_isUnnamedExpr: bool

_is_full_valid() → bool

_is_partially_valid() → bool

classmethod _nextInstId()

Get next instance id

_nop_val

_reinterpret_cast(toType: HdlType)

Cast value or signal of this type to another type of same size.

Parameters:

toType – instance of HdlType to cast into

_rtlDrivers: SetList[HdlStatement, HdlPortItem, 'Operator']

_rtlEndpoints: SetList[HdlStatement | HdlPortItem | 'Operator']

_rtlNextSig: RtlSignal | None

_rtlObjectOrigin

_usedOps: Dict[OperatorCaheKeyType, RtlSignal]

_usedOpsAlias: Dict[OperatorCaheKeyType, Set[OperatorCaheKeyType]]

_walk_public_drivers(seen: set) → Generator[RtlSignal, None, None]

Walk all non hidden signals in an expression

_walk_sensitivity(casualSensitivity: Set[RtlSignalBase], seen: Set[RtlSignalBase], ctx: SensitivityCtx)

Walk expression and collect signals which is this expression sensitive to. (:see: what is signal sensitivity in vhdl/verilog)

Parameters:

• casualSensitivity – set of public signals which is this expression sensitive to but rising/faling edge operator is not present

• seen – set of all seen signals

• ctx – context where sensitivity

singleDriver()

Returns a first driver if signal has only one driver.

staticEval()

hwt.synthesizer.rtlLevel.rtlSignalWalkers module

hwt.synthesizer.rtlLevel.rtlSignalWalkers.discoverEventDependency(sig: RtlSignalBase)

Returns:

generator of tuples (event operator, signal)

hwt.synthesizer.rtlLevel.rtlSignalWalkers.discover_sensitivity_of_sig(signal: RtlSignalBase, seen: set, ctx: SensitivityCtx)

hwt.synthesizer.rtlLevel.statements_to_HdlStmCodeBlockContainers module