Specifications

 2012 Advanced Micro Devices, Inc.
ACPI/SMBUS Controller (bus-0, dev-20, fun-0)
AMD SP5100 Register Programming Requirements
Page 12
ASIC Rev Register Settings Function/Comment
All Revs SP5100 PM_IO 0x7C [1] = 1 Set this bit to 1 to allow pop-up request being latched
during the minimum LDTSTP# assertion time. Pop-up will
happen thereafter even if the request has gone.
All Revs SP5100 PM_IO 0x61 [2] = 0 This bit should be cleared to 0 if C3 pop-up is enabled. If this
bit is set to 1, the BmReq# input or internal bus mastering
will set BM_STS.
All Revs SP5100 PM_IO 0x42 [2] = 0 If this bit is set to 1, the SB will convert C2 into C3, i.e. LVL2
read is treated the same as LVL3 read by hardware. This
feature needs to be turned off because of the following
reason. Some USB applications require continuous DMA
transfer and are very sensitive to C3. The SB is configured
to allow USB to set BM_STS and cause immediate exit from
C3. When BM_STS is set the OS will issue C2 instead of
C3. If C2 is converted into C3, the exit will not happen until
the next interrupt because the OS does not set BM_RLD
before issuing C2 and BM_STS is not considered a break
event. Setting PM_IO 0x9A [4] = 1 can guarantee immediate
exit in this case. But then the C2 to C3 conversion does not
offer any power saving benefit. The feature is pending for
future exploration.
Note: C3 pop-up is recommended for all systems.
Quick reference: Settings for dual-core system:
PM_IO 0x9A [5] = 1
PM_IO 0x9A [4] = 1
PM_IO 0x9A [2] = 1 (default)
PM_IO 0x8F [5] = 1 (default)
PM_IO 0x8F [4] = (1 for SP5100 + RS4x0 NB; 0 for SP5100 + RS690 NB)
PM_IO 0x8B = 0x01 (default)
PM_IO 0x8A = 0x90 (default)
PM_IO 0x88 = 0x06 (default)
PM_IO 0x7C [0] = 1 (default)
PM_IO 0x7C [1] = 1 (default)
PM_IO 0x61 [2] = 0 (default)
PM_IO 0x42 [2] = 0 (default)
Quick reference: Settings for single-core system:
PM_IO 0x9A [5] = 0
PM_IO 0x9A [4] = 0
PM_IO 0x9A [2] = 1 (default)
PM_IO 0x8F [5] = 1 (default)
PM_IO 0x8F [4] = (1 for SP5100 + RS4x0 NB; 0 for SP5100 + RS690 NB)
PM_IO 0x8B = 0x01 (default)
PM_IO 0x8A = 0x90 (default)
PM_IO 0x88 = 0x06 (default)
PM_IO 0x7C [0] = 1 (default)
PM_IO 0x7C [1] = 1 (default)
PM_IO 0x61 [2] = 0 (default)
PM_IO 0x42 [2] = 0 (default)
SATA
USB
SMBUS
PATA
AC97
HD AUDIO
LPC
PCI
For register details refer to
the sections check-marked
in the SP5100 Register
Reference Guide
RTC
ACPI
PM REG
A-LINK
I/O REG
XIOAPIC
x