reSIDfp::EnvelopeGenerator Class Reference

#include <EnvelopeGenerator.h>

Public Member Functions
void	setChipModel (ChipModel chipModel)
void	clock ()
float	output () const
	EnvelopeGenerator ()
void	reset ()
void	writeCONTROL_REG (unsigned char control)
void	writeATTACK_DECAY (unsigned char attack_decay)
void	writeSUSTAIN_RELEASE (unsigned char sustain_release)
unsigned char	readENV () const

Detailed Description

A 15 bit LFSR is used to implement the envelope rates, in effect dividing the clock to the envelope counter by the currently selected rate period.

In addition, another 5 bit counter is used to implement the exponential envelope decay, in effect further dividing the clock to the envelope counter. The period of this counter is set to 1, 2, 4, 8, 16, 30 at the envelope counter values 255, 93, 54, 26, 14, 6, respectively.

Constructor & Destructor Documentation

EnvelopeGenerator()

reSIDfp::EnvelopeGenerator::EnvelopeGenerator ( )

inline

Constructor.

Member Function Documentation

clock()

RESID_INLINE void reSIDfp::EnvelopeGenerator::clock

(

)

SID clocking.

output()

float reSIDfp::EnvelopeGenerator::output ( ) const

inline

Get the Envelope Generator output. DAC imperfections are emulated by using envelope_counter as an index into a DAC lookup table. readENV() uses envelope_counter directly.

readENV()

unsigned char reSIDfp::EnvelopeGenerator::readENV ( ) const

inline

Return the envelope current value.

Returns

envelope counter

reset()

void reSIDfp::EnvelopeGenerator::reset

(

)

SID reset.

setChipModel()

void reSIDfp::EnvelopeGenerator::setChipModel

(

ChipModel

chipModel

)

Set chip model. This determines the type of the analog DAC emulation: 8580 is perfectly linear while 6581 is nonlinear.

Parameters

chipModel

writeATTACK_DECAY()

void reSIDfp::EnvelopeGenerator::writeATTACK_DECAY

(

unsigned char

attack_decay

)

Write Attack/Decay register.

Parameters

attack_decay

attack/decay value

writeCONTROL_REG()

void reSIDfp::EnvelopeGenerator::writeCONTROL_REG

(

unsigned char

control

)

Write control register.

Parameters

control

control register

writeSUSTAIN_RELEASE()

void reSIDfp::EnvelopeGenerator::writeSUSTAIN_RELEASE

(

unsigned char

sustain_release

)

Write Sustain/Release register.

Parameters

sustain_release

sustain/release value

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

• EnvelopeGenerator.h
• EnvelopeGenerator.cpp