Yamaha YMF724F 44-45h Subsystem Vendor ID Write Register, B1211 ......SMOD SB DMA mode

YMF724F

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)

01 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.

September 21, 1998

-20-