Specifications

© 2008 Advanced Micro Devices Inc.
Sample Programs
AMD SB600 BIOS Developer’s Guide (Public Version) Proprietary
Page 60
pop eax
ret
SataClassIdSampleProgram endp
Note: For SB600 revision A11 and revision A12, the SATA controller was at Bus 0, Device 13h,
function 3 and 4.
14.2.7 Disable AC97 Audio or MC97 Modem
For, the AC97 PCI device 14h, functions 5 or 6 may be disabled by setting bits in PM I/O register
59h. The setting of bit 0 will mask out AC97 device 14h, function 5. the setting of bit 1 will mask
out MC97 device 14h, function 6.
Any memory resources assigned to audio and modem PCI devices should also be cleared prior to
disabling these devices.
Sample Program:
The following sample program shows how to disable AC97 audio device 14h, function 5. To
disable MC97 modem device 14h, function 6, set PM I/O register bit 1.
DisableAc97Sample proc near
push eax ; Save registers used by this routine
push dx
; If AC97 audio was previously enabled, clear the memory resources assigned.
mov dx,0CD6h ; PM I/O index register
mov al, 59h ; AC97 Mask register
out dx,al
mov dx,0CD7h ; PM I/O data register
in al,dx ; Read current value
test al,01h ; Is the AC97 audio previously disabled
jnz DisableDone ; Already disabled , so exit the routine
; Clear the address at reg. 10h of AC97 device 14h, function 5 to release the resources
mov dx,0CF8h ; To access PCI configuration register
mov eax,8000A510h ; Device 14h, function 5, register 10h
out dx,eax
mov dx,0CFCh ; To access dword starting at 10h
mov eax,0 ;
out dx,eax
; Disable the AC-97 device by setting PM I/O register 59h bit 0 to 1