reSIDfp::EnvelopeGenerator Class Reference

#include <EnvelopeGenerator.h>

Public Types
enum class	State { ATTACK , DECAY_SUSTAIN , RELEASE }

Public Member Functions
void	clock ()
uint8_t	output () const
void	reset ()
void	writeCONTROL_REG (uint8_t control)
void	writeATTACK_DECAY (uint8_t attack_decay)
void	writeSUSTAIN_RELEASE (uint8_t sustain_release)
uint8_t	readENV () const

Friends
class	State

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.

Member Enumeration Documentation

State

enum class reSIDfp::EnvelopeGenerator::State

strong

The envelope state machine's distinct states. In addition to this, envelope has a hold mode, which freezes envelope counter to zero.

Member Function Documentation

clock()

RESIDFP_INLINE void reSIDfp::EnvelopeGenerator::clock

(

)

SID clocking.

output()

uint8_t reSIDfp::EnvelopeGenerator::output ( ) const

inline

Get the Envelope Generator digital output.

readENV()

uint8_t reSIDfp::EnvelopeGenerator::readENV ( ) const

inline

Return the envelope current value.

Returns

envelope counter value

reset()

void reSIDfp::EnvelopeGenerator::reset

(

)

SID reset.

writeATTACK_DECAY()

void reSIDfp::EnvelopeGenerator::writeATTACK_DECAY

(

uint8_t

attack_decay

)

Write Attack/Decay register.

Parameters

attack_decay

attack/decay value

writeCONTROL_REG()

void reSIDfp::EnvelopeGenerator::writeCONTROL_REG

(

uint8_t

control

)

Write control register.

Parameters

control

control register value

writeSUSTAIN_RELEASE()

void reSIDfp::EnvelopeGenerator::writeSUSTAIN_RELEASE

(

uint8_t

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