pulp::signal::LfsrT< SampleType > Class Template Reference

Configurable Fibonacci linear-feedback shift register with a weighted register-to-output projection. More...

#include <lfsr.hpp>

Public Member Functions
bool	configure (int length, std::uint32_t feedback_mask, std::uint32_t seed) noexcept
bool	set_length (int length) noexcept
bool	set_feedback_mask (std::uint32_t mask) noexcept
void	set_seed (std::uint32_t seed) noexcept
bool	set_weight (std::size_t bit, SampleType weight) noexcept
void	clear_weights () noexcept
bool	set_offset (SampleType offset) noexcept
void	reset () noexcept
std::uint32_t	clock (bool external_bit=false) noexcept
SampleType	weighted_output () const noexcept
SampleType	minimum_output () const noexcept
SampleType	maximum_output () const noexcept
int	length () const noexcept
std::uint32_t	feedback_mask () const noexcept
std::uint32_t	seed () const noexcept
std::uint32_t	state () const noexcept
SampleType	offset () const noexcept

Static Public Member Functions
static constexpr int	latency_samples () noexcept
static constexpr int	tail_samples () noexcept

Static Public Attributes
static constexpr int	kMinLength = 2
static constexpr int	kMaxLength = 32
static constexpr int	kDefaultLength = 8
static constexpr std::uint32_t	kDefaultFeedbackMask = 0x8Eu
static constexpr std::uint32_t	kDefaultSeed = 0b10110100u

Detailed Description

template<typename SampleType = float>
class pulp::signal::LfsrT< SampleType >

Configurable Fibonacci linear-feedback shift register with a weighted register-to-output projection.

The register shifts toward the most-significant bit. On each clock(), the new bit is the parity of state & feedback_mask, optionally XOR-ed with an external bit. Bit weights are expressed directly in caller-defined output units; weighted_output() is offset + sum(weight[i]) for every high bit. Its exact range is therefore reported by minimum_output() and maximum_output().

Length is 2..32 bits. A zero seed is intentionally legal and absorbing unless an external high bit is clocked; this preserves Rungler patch semantics. A maximal-period sequence requires a nonzero seed and a primitive-polynomial feedback mask chosen by the caller. The default mask 0x8e is audited by the direct full-period oracle as a primitive 8-bit configuration; arbitrary caller masks intentionally make no period claim.

RT contract: all methods are bounded scalar/array work with no allocation, locks, I/O, or hidden entropy. reset() restores the public seed exactly. Latency and tail are both zero samples.

Member Function Documentation

clear_weights()

template<typename SampleType = float>

void pulp::signal::LfsrT< SampleType >::clear_weights ( )

inlinenoexcept

clock()

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::clock ( bool external_bit = false )

inlinenoexcept

configure()

template<typename SampleType = float>

bool pulp::signal::LfsrT< SampleType >::configure ( int length, std::uint32_t feedback_mask, std::uint32_t seed )

inlinenoexcept

feedback_mask()

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::feedback_mask ( ) const

inlinenoexcept

latency_samples()

template<typename SampleType = float>

constexpr int pulp::signal::LfsrT< SampleType >::latency_samples ( )

inlinestaticconstexprnoexcept

length()

template<typename SampleType = float>

int pulp::signal::LfsrT< SampleType >::length ( ) const

inlinenoexcept

maximum_output()

template<typename SampleType = float>

SampleType pulp::signal::LfsrT< SampleType >::maximum_output ( ) const

inlinenoexcept

minimum_output()

template<typename SampleType = float>

SampleType pulp::signal::LfsrT< SampleType >::minimum_output ( ) const

inlinenoexcept

offset()

template<typename SampleType = float>

SampleType pulp::signal::LfsrT< SampleType >::offset ( ) const

inlinenoexcept

reset()

template<typename SampleType = float>

void pulp::signal::LfsrT< SampleType >::reset ( )

inlinenoexcept

seed()

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::seed ( ) const

inlinenoexcept

set_feedback_mask()

template<typename SampleType = float>

bool pulp::signal::LfsrT< SampleType >::set_feedback_mask ( std::uint32_t mask )

inlinenoexcept

set_length()

template<typename SampleType = float>

bool pulp::signal::LfsrT< SampleType >::set_length ( int length )

inlinenoexcept

set_offset()

template<typename SampleType = float>

bool pulp::signal::LfsrT< SampleType >::set_offset ( SampleType offset )

inlinenoexcept

set_seed()

template<typename SampleType = float>

void pulp::signal::LfsrT< SampleType >::set_seed ( std::uint32_t seed )

inlinenoexcept

set_weight()

template<typename SampleType = float>

bool pulp::signal::LfsrT< SampleType >::set_weight ( std::size_t bit, SampleType weight )

inlinenoexcept

state()

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::state ( ) const

inlinenoexcept

tail_samples()

template<typename SampleType = float>

constexpr int pulp::signal::LfsrT< SampleType >::tail_samples ( )

inlinestaticconstexprnoexcept

weighted_output()

template<typename SampleType = float>

SampleType pulp::signal::LfsrT< SampleType >::weighted_output ( ) const

inlinenoexcept

Member Data Documentation

kDefaultFeedbackMask

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::kDefaultFeedbackMask = 0x8Eu

staticconstexpr

kDefaultLength

template<typename SampleType = float>

int pulp::signal::LfsrT< SampleType >::kDefaultLength = 8

staticconstexpr

kDefaultSeed

template<typename SampleType = float>

std::uint32_t pulp::signal::LfsrT< SampleType >::kDefaultSeed = 0b10110100u

staticconstexpr

kMaxLength

template<typename SampleType = float>

int pulp::signal::LfsrT< SampleType >::kMaxLength = 32

staticconstexpr

kMinLength

template<typename SampleType = float>

int pulp::signal::LfsrT< SampleType >::kMinLength = 2

staticconstexpr

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The documentation for this class was generated from the following file:

• /home/runner/work/pulp/pulp/core/signal/include/pulp/signal/lfsr.hpp