YMF724F
September 21, 1998
-20-
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
“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
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.
SIEN IMOD Interrupt protocol
0 0 Legacy interrupt (IRQs) (default)
0 1 PCI interrupt (INTA#)
1 * Serialized IRQ
44-45h: Subsystem Vendor ID Write Register
Read / Write
Default: 1073h
Access Bus Width: 16-bit
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Subsystem Vendor ID Write
b[15:0]........Subsystem Vendor ID Write Register
This register sets the Subsystem Vendor ID that is read from 2C-2Dh (Subsystem Vendor ID register).
The default value is the YAMAHA Vendor ID, 1073h. IHVs must change this ID to their Vendor ID in
the BIOS POST routine.
In case EEPROM connects externally, this register is invalid, and do not reflect to Subsystem Vendor ID.