cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 482

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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PMC Register Descriptions
5.18.2.4
ACPI I/O Offset
Type
Reset Value
PM2_CNT is the Control register for enabling/disabling the system arbiter. This register is not implemented. Writes “don’t
care. Reads return 0. This register may be accessed with 8-bit or 16-bit I/O.
15:14
12:10
15
Bit
8:3
13
9
2
1
0
14
PM Control 2 (PM2_CNT)
Name
RSVD
SLP_EN (WO)
SLP_TYPx
IGNORE
RSVD
GBL_RLS
BM_RLD
SCI_EN
13
0Ch
R/W
0000h
12
RSVD
11
Description
Reserved. By convention write 0, but other values are “don’t care”. Reads always
return 0.
Sleep Enable (Write Only). This is a write-only bit and reads to it always return 0. Set-
ting this bit causes the system to sequence into the Sleep state defined by SLP_TYPx
(bits [12:10]).
After the delay in SLP_DELAY (PMS I/O Offset 00h[11:0]), the system state begins the
move from Working to Sleeping or Standby state. The Sleep Request/Sleep Acknowl-
edge sequenced is started. The sequence may be aborted by writing SLP_EN_INDIC
(PMS I/O Offset 00h[15]).
Sleep Type. Defines the type of Sleep state the system enters when SLP_EN (bit 13)
is set to 1. Reads always return the value written.
These bits do not directly affect the internal hardware, but are required by the ACPI
specification. When this register is accessed, VSA code traps the access and transfers
bits written here to the appropriate locations to set up the desired power management
mode.
The Sleep type is directly controlled by GLCP settings, individual GeodeLink Device
Power Management MSR settings, and PML settings.
Ignore. By convention not used by ACPI software. Software always writes 0.
If a 1 was written to bit 2 (GBL_RLS), this bit is set, that is, a read of this bit returns a 1.
Write 1 to clear; writing 0 has no effect.
Reserved. By convention write 0, but other values are “don’t care”. Reads always
return 0.
Global Lock Release. This is the “release of global lock” bit. The ACPI driver writes
this bit to a 1 to rise an event to the BIOS. The write indicates the release of global lock.
Reads always return 0.
Writing a 1 to this bit sets bit 9 (IGNORE).
Bus Master RLD. When high, this bit allows the generation of a bus master request to
cause any processor in the C3 state to transition to the C0 state. Reads return the
value written. In the CS5535, the C3 state is NOT supported. Other than serving as an
indicator, this bit does nothing.
SCI Enable. When low, indicates native power management mode. When high, indi-
cates ACPI mode. Reads return the value written. Other than serving as an indicator,
this bit does not directly affect the hardware.
(Continued)
10
PM1_CNT Bit Descriptions
PM2_CNT Register Map
9
8
482
7
6
5
RSVD
4
3
2
1
Revision 0.8
ARB_
DIS
0