AMD SB600 User Manual
Page 200

©2008 Advanced Micro Devices, Inc.
AC ’97 Controller Functional Descriptions
AMD SB600 Register Reference Manual
Proprietary
Page 200
Revision ID/Class Code - R - 32 bits - [PCI_Reg: 08h]
Field Name
Bits
Default
Description
Revision ID
7:0
00h
Revision ID.
Class Code
31:8
040100h
Class Code.
Revision ID/Class Code Register: This read only register contains the device’s revision information and generic
function.
Cache Line Size - RW - 8 bits - [PCI_Reg: 0Ch]
Field Name
Bits
Default
Description
Cache Line Size
7:0
00h
Cache Line Size.
Cache Line Size Register: This register specifies the system cache line size.
Latency Timer - RW - 8 bits - [PCI_Reg: 0Dh]
Field Name
Bits
Default
Description
Latency Timer
7:0
00h
Latency Timer.
Latency Timer Register: This register specifies the value of the Latency Timer in units of PCICLKs.
Header Type - R - 8 bits - [PCI_Reg: 0Eh]
Field Name
Bits
Default
Description
Header Type
7:0
80h
Header Type.
Header Type Register: This register identifies the type of the predefined header in the configuration space. Since
SB600 is a multifunction device, the most significant bit is set.
BIST- R – 8 bits – [PCI_Reg: 0Fh]
Field Name
Bits
Default
Description
BIST 7:0
00h
BIST
register.
Built-in Self Test Register: This register is used for control and status for Built-in Self Test. Ac97 has no BIST
modes.
Base Address Reg 0- RW - 32 bits – [PCI_Reg: 10h]
Field Name
Bits
Default
Description
MemoryIndicator
0
0b
Always 0; meaning it is always memory mapped
Type
2:1
00b
Always 0; meaning it can be located anywhere in 32 bit
address space
Prefetchable
3
0b
Always 0; meaning it is not prefetchable
Reserved
7:4
0h
Always 0; meaning the memory mapped registers occupy
256 bytes
BAR0
31:8
0000_00h
Base address register 0. Defines the base address for the
memory mapped register space of audio. If index 50h, bit 3
is set, bits [13:8] of this register become unwritable. The
effect will cause the OS to allocate a wider memory map for
this controller.
Base Address Reg 1- RW - 32 bits – [PCI_Reg: 14h]
Field Name
Bits
Default
Description
MemoryIndicator
0
0b
This bit will return 1 if index 50h, bit [1] is set. 1 means IO
mapping
Type
2:1
00b
Always 0; meaning that it can be located anywhere in 32 bit
address space.
Prefetchable
3
0b
Always 0; meaning that it is not prefetchable.