YMF754 Datasheet, PDF (20/60 Pages) YAMAHA CORPORATION – DS-1E

YMF754
b15..............LAD: Legacy Audio Disable
This bit disables the Legacy Audio block.
“0”: Enables the Legacy Audio block
“1”: Disables the Legacy Audio block
(default)
When this bit is set to “1”, DS-1E does not respond to the I/O Target transaction for legacy I/O address on
the PCI bus.
42-43h: Extended Legacy Audio Control
Read / Write
Default: 0000h
Access Bus Width: 8, 16, 32-bit
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
IMOD SBVER
SMOD
-
- MAIM -
-
-
-
-
-
-
-
b8................MAIM: MPU401 Acknowledge Interrupt Mask
This bit determine whether interrupt is asserted when the acknowledge, which is occurred by changing
MPU401 mode form default to UART, is returned.
“0”: Interrupt is asserted when the acknowledge is returned.
(default)
“1”: Interrupt is masked when the acknowledge is returned.
b[12:11] ......SMOD: SB DMA mode
These bits determine the protocol to achieve the DMAC(8237) function on the PCI bus.
“0”:
PC/PCI
(default)
“1”:
reserved
“2”:
Distributed DMA (D-DMA)
“3”
reserved
b[14:13] ......SBVER: SB Version Select
These bits set the version of the SB Pro DSP. The value set in these bits is returned by sending the E1h
DSP command.
“0”:
ver 3.01
(default)
“1”:
ver 2.01
“2”:
ver 1.05
“3”:
reserved
b15..............IMOD: Legacy IRQ mode
The legacy interrupt protocol is selected with IMOD and SIEN. Refer to the explanation of SIEN bit.
June 28, 1999
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