©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 Al ways 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 Al ways 0; meaning that it is not prefetchable.