recti::ElmoreDelayCalculator Class Reference

Implements the Elmore delay model for RC trees. More...

#include <dme_algorithm.hpp>

Inheritance diagram for recti::ElmoreDelayCalculator:

Collaboration diagram for recti::ElmoreDelayCalculator:

Public Member Functions
	ElmoreDelayCalculator (double unit_resistance=1.0, double unit_capacitance=1.0)
double	calculate_wire_delay (int length, double load_capacitance) const override
	Calculates the delay of a wire segment.
double	calculate_wire_delay_per_unit (double load_capacitance) const override
	Calculates the delay per unit length of a wire.
double	calculate_wire_capacitance (int length) const override
	Calculates the capacitance of a wire segment.
TappingResult	calculate_tapping_point (int distance, double left_delay, double right_delay, double left_capacitance, double right_capacitance) const override
	Elmore-model tapping point.
Public Member Functions inherited from recti::DelayCalculator
	DelayCalculator ()=default
	DelayCalculator (const DelayCalculator &)=default
DelayCalculator &	operator= (const DelayCalculator &)=default
	DelayCalculator (DelayCalculator &&)=default
DelayCalculator &	operator= (DelayCalculator &&)=default
virtual	~DelayCalculator ()=default

Detailed Description

Implements the Elmore delay model for RC trees.

The Elmore delay model is a widely used approximation for delay in RC interconnects. It considers both the resistance and capacitance of the wires and the downstream load. Delay = R_wire * (C_wire/2 + C_load).

Constructor & Destructor Documentation

ElmoreDelayCalculator()

recti::ElmoreDelayCalculator::ElmoreDelayCalculator ( double  unit_resistance = 1.0, double  unit_capacitance = 1.0  )

inline

Member Function Documentation

calculate_tapping_point()

TappingResult recti::ElmoreDelayCalculator::calculate_tapping_point ( int  distance, double  left_delay, double  right_delay, double  left_capacitance, double  right_capacitance  ) const

overridevirtual

Elmore-model tapping point.

Solves for the optimal tapping point z (fraction of distance from left) to achieve prescribed skew between the children considering their delays and capacitances:

z = (skew + R*(C_r + C_w/2)) / (R*(C_w + C_r + C_l))

where R = distance * unit_resistance, C_w = distance * unit_capacitance. When the raw extend_left falls below 0 or above distance, clamping and elongation logic applies (see LinearDelayCalculator).

Implements recti::DelayCalculator.

calculate_wire_capacitance()

double recti::ElmoreDelayCalculator::calculate_wire_capacitance ( int  length ) const

inlineoverridevirtual

Calculates the capacitance of a wire segment.

Parameters

length

The length of the wire.

Returns

The calculated wire capacitance.

Implements recti::DelayCalculator.

calculate_wire_delay()

double recti::ElmoreDelayCalculator::calculate_wire_delay ( int  length, double  load_capacitance  ) const

inlineoverridevirtual

Calculates the delay of a wire segment.

Parameters

length	The length of the wire segment.
load_capacitance	The total capacitance driven by this wire segment.

Returns

The calculated wire delay in time units.

Implements recti::DelayCalculator.

calculate_wire_delay_per_unit()

double recti::ElmoreDelayCalculator::calculate_wire_delay_per_unit ( double  load_capacitance ) const

inlineoverridevirtual

Calculates the delay per unit length of a wire.

Parameters

load_capacitance

The total capacitance driven by this wire segment.

Returns

The delay per unit length in time units per length unit.

Implements recti::DelayCalculator.

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

• recti/dme_algorithm.hpp