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AC’97 Audio Controller Registers (D31:F5)
12-14
82801AA and 82801AB Datasheet
12.2.8
GLOB_CNT—Global Control Register
I/O Address:
Default Value:
Lockable:
NABMBAR + 2Ch
00000000h
No
Attribute:
Size:
Power Well:
R/W
32 bits
Core
12.2.9
GLOB_STA—Global Status Register
I/O Address:
Default Value:
Lockable:
NABMBAR + 30h
00000000h
No
Attribute:
Size:
Power Well:
R/W
32 bits
Core
Bit
Description
31:6
Reserved.
5
Secondary Resume Interrupt Enable
1 = Enable an interrupt to occur when the secondary codec causes a resume event on the AC-link.
0 = Disable
4
Primary Resume Interrupt Enable
1 = Enable an interrupt to occur when the primary codec causes a resume event on the AC-link.
0 = Disable
3
ACLINK Shut Off
1 = Drive all AC’97 outputs low and turn off all AC’97 input buffer enables.
2
AC’97 Warm Reset.
1 = Writing a "1" to this bit causes a warm reset to occur on the AC-link. The warm reset awakens a
suspended codec without clearing its internal registers. If software attempts to perform a warm
reset while bit_clk is running, the write is ignored and the bit does not change. This bit is self-
clearing (it remains set until the reset completes and bit_clk is seen on the ACLink, after which it
clears itself).
1
AC ‘97 Cold Reset#.
0 = Writing a "0" to this bit causes a cold reset to occur throughout the AC ‘97 circuitry. All data in
the controller and the codec is lost. Software needs to clear this bit no sooner than the minimum
number of ms have elapsed. This bit defaults to 0 and hence after reset, the driver needs to set
this bit to a 1. The value of this bit is retained after suspends; hence, if this bit is set to a 1 prior
to suspending, a cold reset is not generated automatically upon resuming.
NOTE:
This bit is in the Resume well, not in the Core well.
0
GPI Interrupt Enable (GIE).
This bit controls whether the change in status of any GPI causes an
interrupt.
1 = The change on value of a GPI causes an interrupt and sets bit 0 of the Global Status Register.
0 = Bit 0 of the Global Status Register is set, but an interrupt is not generated.
Bit
Description
31:18
Reserved.
17
MD3:
Power down semaphore for Modem. This bit is used by software in conjunction with the AD3
bit to coordinate the entry of the two codecs into D3 state. This bit resides in the resume well and
maintain context across power states.
16
AD3:
Power down semaphore for Audio. This bit is used by software in conjunction with the MD3 bit
to coordinate the entry of the two codecs into D3 state. This bit resides in the resume well and
maintain context across power states.