libsidplayfp  1.8.3
Public Member Functions | List of all members
reSIDfp::EnvelopeGenerator Class Reference

#include <EnvelopeGenerator.h>

Public Member Functions

void setChipModel (ChipModel chipModel)
 
void clock ()
 
short 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 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

reSIDfp::EnvelopeGenerator::EnvelopeGenerator ( )
inline

Constructor.

Member Function Documentation

RESID_INLINE void reSIDfp::EnvelopeGenerator::clock ( )

SID clocking.

short 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.

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

Return the envelope current value.

Returns
envelope counter
void reSIDfp::EnvelopeGenerator::reset ( )

SID reset.

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
void reSIDfp::EnvelopeGenerator::writeATTACK_DECAY ( unsigned char  attack_decay)

Write Attack/Decay register.

Parameters
attack_decayattack/decay value
void reSIDfp::EnvelopeGenerator::writeCONTROL_REG ( unsigned char  control)

Write control register.

Parameters
controlcontrol register
void reSIDfp::EnvelopeGenerator::writeSUSTAIN_RELEASE ( unsigned char  sustain_release)

Write Sustain/Release register.

Parameters
sustain_releasesustain/release value

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