soundbox.h File Reference

Low-level access to the SoundBox. More...

Go to the source code of this file.

Enumerations
enum	adpcm_rate { ADPCM_RATE_32000 = 0, ADPCM_RATE_16000 = 1, ADPCM_RATE_8000 = 2, ADPCM_RATE_4000 = 3 }
	ADPCM sample rate. More...
Functions
void	eris_low_psg_set_main_volume (u8 left, u8 right)
	Set main volume.
void	eris_low_psg_set_channel (u8 chan)
	Set the active channel to operate on.
void	eris_low_psg_set_freq (u16 freq)
	Set the frequency of the active channel.
void	eris_low_psg_set_volume (u8 vol, u8 on, u8 dda)
	Set the volume (and some controls) of the active channel.
void	eris_low_psg_set_balance (u8 left, u8 right)
	Set the balance on the active channel.
void	eris_low_psg_waveform_data (u8 sample)
	Write waveform data for the active channel.
void	eris_low_psg_set_noise (u8 freq, u8 enabled)
	Set noise control data for the active channel.
void	eris_low_psg_set_lfo_freq (u8 freq)
	Set LFO frequency.
void	eris_low_psg_set_lfo_control (int on, int ctrl)
	Set LFO controls.
void	eris_low_adpcm_set_control (adpcm_rate rate, u8 ch0_interp, u8 ch1_interp, u8 ch0_reset, u8 ch1_reset)
	Set ADPCM controls.
void	eris_low_adpcm_set_volume (u8 chan, u8 left, u8 right)
	Set ADPCM channel volume.
void	eris_low_cdda_set_volume (u8 left, u8 right)
	Set CDDA volume.

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Detailed Description

Low-level access to the SoundBox.

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Enumeration Type Documentation

enum adpcm_rate

ADPCM sample rate.

Enumerator:

ADPCM_RATE_32000	32kHz sample rate
ADPCM_RATE_16000	16kHz sample rate
ADPCM_RATE_8000	8kHz sample rate
ADPCM_RATE_4000	4kHz sample rate

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Function Documentation

void eris_low_adpcm_set_control	(	adpcm_rate	rate,
		u8	ch0_interp,
		u8	ch1_interp,
		u8	ch0_reset,
		u8	ch1_reset
	)

Set ADPCM controls.

Parameters:

rate	Sample rate for the ADPCM.
ch0_interp	Whether Channel 0 has linear interpolation enabled.
ch1_interp	Whether Channel 1 has linear interpolation enabled.
ch0_reset	If set, reset Channel 0.
ch1_reset	If set, reset Channel 1.

void eris_low_adpcm_set_volume	(	u8	chan,
		u8	left,
		u8	right
	)

Set ADPCM channel volume.

Parameters:

chan	Which channel to set the volume of.
left	Left speaker volume. (0 ~ 63)
right	Right speaker volume. (0 ~ 63)

void eris_low_cdda_set_volume	(	u8	left,
		u8	right
	)

Set CDDA volume.

Parameters:

left	Left speaker volume. (0 ~ 63)
right	Right speaker volume. (0 ~ 63)

void eris_low_psg_set_balance	(	u8	left,
		u8	right
	)

Set the balance on the active channel.

Parameters:

left	Left speaker output volume. (0 ~ 15)
right	Right speaker output volume. (0 ~ 15)

void eris_low_psg_set_channel

(

u8

chan

)

Set the active channel to operate on.

This affects which channel is changed for the functions eris_low_psg_set_freq(), eris_low_psg_set_volume(), eris_low_psg_set_balance(), eris_low_psg_waveform_data(), and eris_low_psg_set_noise().

Parameters:

chan	The channel to become active. (0 ~ 5)

void eris_low_psg_set_freq

(

u16

freq

)

Set the frequency of the active channel.

Parameters:

freq	The frequency of the channel. 12bit. Calculated as n = (3580000 / 32) / freq

void eris_low_psg_set_lfo_control	(	int	on,
		int	ctrl
	)

Set LFO controls.

Parameters:

on	Whether the LFO is enabled or not.
ctrl	LFO control. Influence is not simple; see hardware documentation.

void eris_low_psg_set_lfo_freq

(

u8

freq

)

Set LFO frequency.

Parameters:

freq	The LFO's new frequency value. Influence is not simple; see hardware documentation.

void eris_low_psg_set_main_volume	(	u8	left,
		u8	right
	)

Set main volume.

Parameters:

left	Left speaker output volume. (0 ~ 15)
right	Right speaker output volume. (0 ~ 15)

void eris_low_psg_set_noise	(	u8	freq,
		u8	enabled
	)

Set noise control data for the active channel.

Only works on the last 2 channels (4 and 5).

Parameters:

freq	Frequency of the noise. 5bit. Calculated as n = (3580000 / 32) / freq
enabled	Whether the channel should or should not output noise.

void eris_low_psg_set_volume	(	u8	vol,
		u8	on,
		u8	dda
	)

Set the volume (and some controls) of the active channel.

Parameters:

vol	Volume of the channel. (0 ~ 31)
on	Controls whether the channel is on or off.
dda	Direct DAC access control. When enabled, waveform data is streamed through eris_low_psg_waveform_data().

void eris_low_psg_waveform_data

(

u8

sample

)

Write waveform data for the active channel.

If DDA is off, writes to the waveform buffer and increases the index. If it's on, it changes the current sample being played.

Parameters:

sample

A 5bit unsigned sample. (0 ~ 31)