YMF724F
b[7:6] ..........SDMA: Sound Blaster DMA-8 Channel Select
These bits select the DMA channel for the Sound Blaster Pro block.
“0”:
“1”:
“2”:
“3”:
DMA ch0
DMA ch1
reserved
(default)
DMA ch3
b[10:8] ........SBIRQ: Sound Blaster IRQ Channel Select
These bits select the interrupt channel for the Sound Blaster Pro block.
“0”:
“1”:
“2”:
“3”:
“4”:
IRQ5
IRQ7
IRQ9
IRQ10
IRQ11
(default)
“5” - “7”: reserved.
b[13:11] ......MPUIRQ: MPU401 IRQ Channel Select
When MIEN is set to “1”, these bits select the interrupt channel for the MPU401 block.
“0”:
“1”:
“2”:
“3”:
“4”:
IRQ5
IRQ7
IRQ9
IRQ10
IRQ11
(default)
“5” - “7”: reserved
Same interrupt channels can be assigned to SBIRQ and MPUIRQ.
b14..............SIEN: Serialized IRQ enable
DS-1 supports 3 types of interrupt protocols: PCI interrupt (INTA#), Legacy interrupt (IRQs) and
Serialized IRQ. The interrupt protocol is selected with IMOD and SIEN as follows.
The interrupt channels for IRQs and Serialized IRQ are determined by SBIRQ and MPUIRQ,. Only one
protocol can be used at once.
SIEN
IMOD
Interrupt protocol
0
0
1
0
1
*
Legacy interrupt (IRQs)
PCI interrupt (INTA#)
Serialized IRQ
(default)
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-1 does not respond to the I/O Target transaction for legacy I/O address on
the PCI bus.
January 14, 1999
-18-
YAMAHA [ YAMAHA CORPORATION ]
