YMF724 ETC, YMF724 Datasheet - Page 40

• Manufacturer Part Number: YMF724
• Description: high performance audio controller for the PCI Bus
• Manufacturer: ETC

YMF724F
4. Interrupt Routing
5. Digital Audio Interface
4-1. Serialized IRQ
DS-1 supports three types of interrupts, interrupt signal on the PCI bus (INTA#), interrupt signal on the ISA
bus (IRQ[5,7,9,10,11]), and Serialized IRQ.
The IRQs on DS-1 are routed as shown below.
PCI Audio can only use INTA#, but the Sound Blaster Pro and MPU401 blocks of the Legacy Audio Block
can use any of the three protocols.
The protocol can be switched using 40-43h (Legacy Audio Control Register) of the PCI Configuration
Register.
Serialized IRQ is a method to encode IRQs of 15 channels into one signal.
DS-1 provides the SERIRQ# pin to support Serialized IRQ.
Only one channel out of the 5 channels, IRQ5, IRQ7, IRQ9, IRQ10, and IRQ11, can be encoded into the
IRQ/Data frame of Serialized IRQ.
The IRQ channel is selected using 40h-43h (Legacy Audio Control Register) of the PCI Configuration
Register.
DS-1 only supports SPDIF output conforming to IEC958. The only supported Fs is 48 kHz. It can be
selectable from the Dolby Digital (AC-3) encoded data or the result of Digital Mixing.
SERIRQ#
INTA#
IRQ10
IRQ11
IRQ5
IRQ7
IRQ9
SERIRQ
ISA IRQ
INTA
-40-
SIEN=0, IMOD=1
SIEN=0, IMOD=0
SIEN=1, IMOD=*
SIEN=0, IMOD=1
SIEN=0, IMOD=0
SIEN=1, IMOD=*
SIEN, IMOD
Select Signal
Select Signal
IRQ
IRQ
SBIRQ[2:0]
MPUIRQ[2:0]
Sound Blaster Pro
January 14, 1999
PCI Audio
MPU401