Yamaha OPL3-SA3 YMF715E, Miscellaneous, WSS DMA Base counter R/W, WSS Interrupt Scan out/in R/W

YMF715E

Miscellaneous:

	Index	D7		D6	D5	D4	D3	D2	D1	D0
	0Ah	VEN		-	-	MCSW	MODE	VER2	VER1	VER0
	VEN...		This bit enables the hardware volume control. Default is VEN=“1”.
	MCSW...		This bit determines whether Rch of Mic input or loopback of monaural
			output is connected to A/D. This will be useful to support the echo
			cancellation. When “0” is set to this bit, Rch of Mic input is selected.
	MODE...		This bit indicates the SB or WSS mode. If MODE=0, it is the SB mode.
			This bit is read only.
	VER2-0...		These bits indicate the version of OPL3-SA3 and read only (VER2=“1”,
			VER1=“0”, VER0=“0”).
	default : 84h
WSS DMA Base counter (R/W):
	Index	D7		D6	D5	D4	D3	D2	D1	D0
	0Bh				Playback Base Counter (Low)
	0Ch				Playback Base Counter (High)
	0Dh				Recording Base Counter (Low)
	0Eh				Recording Base Counter (High)

These registers are to load the value to WSS DMA base counter and read out the present value. Initial value is FFh.

In case of loading the value, both high and low bytes are loaded to internal DMA counter when the high byte is written. The value set to this register is “(the number of transfer byte) -1” that is same as WSS CODEC indirect register 0Eh, 0Fh, 1Eh and 1Fh.

When read these registers, the present value of DMA base counter is read out.

These registers are used mainly to support the suspend/resume feature that is very important for Notebook PC application.

WSS Interrupt Scan out/in (R/W):

Index	D7	D6	D5	D4	D3	D2	D1	D0
0Fh	-	-	-	-	-	STI	SCI	SPI

Use the bits in this register to set WSS interrupt-flags(WSS CODEC indirect Register, index 18h, D6-D4 bits).

STI...	“1” in this bit means TI=“1” and corresponding IRQ active.
SCI...	“1” in this bit means CI=“1” and corresponding IRQ active.
SPI...	“1” in this bit means PI=“1” and corresponding IRQ active.
default : 00h
Notice)

To make IRQ active, it is necessary to set “1” to WSS CODEC indirect register index 0Ah IEN bit.

May 21, 1997

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