reSID::EnvelopeGenerator Class Reference

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

Public Member Functions
void	set_chip_model (chip_model model)
void	clock ()
void	clock (cycle_count delta_t)
void	reset ()
void	writeCONTROL_REG (reg8)
void	writeATTACK_DECAY (reg8)
void	writeSUSTAIN_RELEASE (reg8)
reg8	readENV ()
short	output ()

Protected Member Functions
void	set_exponential_counter ()
void	state_change ()

Protected Attributes
reg16	rate_counter
reg16	rate_period
reg8	exponential_counter
reg8	exponential_counter_period
reg8	new_exponential_counter_period
reg8	envelope_counter
reg8	env3
cycle_count	envelope_pipeline
cycle_count	exponential_pipeline
cycle_count	state_pipeline
bool	hold_zero
bool	reset_rate_counter
reg4	attack
reg4	decay
reg4	sustain
reg4	release
reg8	gate
State	state
State	next_state
chip_model	sid_model

Static Protected Attributes
static reg16	rate_counter_period []
static reg8	sustain_level []
static unsigned short	model_dac [2][1<< 8]

Friends
class	SID

Member Function Documentation

state_change()

RESID_INLINE void reSID::EnvelopeGenerator::state_change ( )

protected

This is what happens on chip during state switching, based on die reverse engineering and transistor level emulation.

Attack

0 - Gate on 1 - Counting direction changes During this cycle the decay rate is "accidentally" activated 2 - Counter is being inverted Now the attack rate is correctly activated Counter is enabled 3 - Counter will be counting upward from now on

Decay

0 - Counter == $ff 1 - Counting direction changes The attack state is still active 2 - Counter is being inverted During this cycle the decay state is activated 3 - Counter will be counting downward from now on

Release

0 - Gate off 1 - During this cycle the release state is activated if coming from sustain/decay *2 - Counter is being inverted, the release state is activated *3 - Counter will be counting downward from now on

(* only if coming directly from Attack state)

Freeze

0 - Counter == $00 1 - Nothing 2 - Counter is disabled

Member Data Documentation

model_dac

unsigned short reSID::EnvelopeGenerator::model_dac

staticprotected

Initial value:

= {
  {0},
  {0},
}

rate_counter_period

reg16 reSID::EnvelopeGenerator::rate_counter_period

staticprotected

Initial value:

= {
      8,  
     31,  
     62,  
     94,  
    148,  
    219,  
    266,  
    312,  
    391,  
    976,  
   1953,  
   3125,  
   3906,  
  11719,  
  19531,  
  31250   
}

sustain_level

reg8 reSID::EnvelopeGenerator::sustain_level

staticprotected

Initial value:

= {
  0x00,
  0x11,
  0x22,
  0x33,
  0x44,
  0x55,
  0x66,
  0x77,
  0x88,
  0x99,
  0xaa,
  0xbb,
  0xcc,
  0xdd,
  0xee,
  0xff,
}

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

• envelope.h
• envelope.cc