APU register table/DSP voice

See: APU register table

This table lists the 2 common names for the S-DSP voice registers.

Name		Address	Bits	Type	Notes
VxVOLL	VOL (L)	$X0	SVVV VVVV	RW	Left channel volume, signed.
VxVOLR	VOL (R)	$X1	SVVV VVVV	RW	Right channel volume, signed.
VxPITCHL	P (L)	$X2	LLLL LLLL	RW	Low 8 bits of sample pitch.
VxPITCHH	P (H)	$X3	--HH HHHH	RW	High 6 bits of sample pitch.
VxSCRN	SCRN	$X4	SSSS SSSS	RW	Selects a sample source entry from the directory (see DIR below).
VxADSR1	ADSR (1)	$X5	EDDD AAAA	RW	ADSR enable (E), decay rate (D), attack rate (A).
VxADSR2	ADSR (2)	$X6	SSSR RRRR	RW	Sustain level (S), sustain rate (R).
VxGAIN	GAIN	$X7	0VVV VVVV 1MMV VVVV	RW	Mode (M), value (V).
VxENVX	ENVX	$X8	0VVV VVVV	R	Reads current 7-bit value of ADSR/GAIN envelope.
VxOUTX	OUTX	$X9	SVVV VVVV	R	Reads signed 8-bit value of current sample wave multiplied by ENVX, before applying VOL.