cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 75

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

Revision 0.8
4.1
Many traditional architectures use buses to connect mod-
ules together, usually requiring unique addressing for each
register in every module. This requires that some kind of
house-keeping be done as new modules are designed and
new devices are created from the module set. Module
select signals can be used to create the unique addresses,
but that can get cumbersome and it requires that the mod-
ule selects be sourced from some centralized location.
To alleviate this issue, National developed an internal bus
architecture called GeodeLink. The GeodeLink architecture
connects the internal modules of a device using the data
channels provided by GeodeLink Interface Units (GLIUs).
Using GLIUs, all internal module port addresses are
derived from the distinct port that the module is connected
to. In this way, a module’s Model Specific Registers (MSRs)
do not have unique addresses until a device is defined.
Also, as defined by the GeodeLink architecture, a module’s
port address depends on the location of the module sourc-
ing the cycle, or source module.
The CS5535 incorporates one GLIU into its device archi-
tecture. Except for the configuration registers that are
required for x86 compatibility, all internal registers are
accessed through a Model Specific Register (MSR) set.
MSRs have a 32-bit address space and a 64-bit data
Device
USBC1
USBC2
ATAC
DD
ACC
GLPCI_SB
Spares
GEODELINK INTERFACE UNIT
Descriptor Type
Table 4-2. GLIU Descriptors Reserved for GeodeLink Devices
P2D_BMK
P2D_BMK
P2D_BM
P2D_BM
P2D_BM
IOD_BM
IOD_BM
IOD_SC
IOD_BM
IOD_BM
IOD_SC
IOD_SC
IOD_SC
IOD_SC
IOD_BM
IOD_BM
IOD_BM
IOD_SC
# of Descriptors
1
1
1
1
1
3
1
1
1
3
1
1
1
1
2
1
1
1
75
space. The full 64-bit data space is always read or written
when accessed.
4.1.1
Table 4-1 shows the GeodeLink Devices connected to each
of the seven GLIU ports on CS5535.
4.1.2
Table 4-2 shows the descriptors reserved for each
GeodeLink Device.
Usage
Do not hit on keyboard emulation registers.
Do not hit on keyboard emulation registers.
For IDE master registers.
Defaults to 1Fxh.
Defaults to 3F6h.
COM ports legacy power management.
For secondary IDE trapping to 17xh.
For secondary IDE trapping to 376h.
Keyboard legacy power management.
LPC ports legacy power management.
Floppy legacy power management.
For memory space registers.
For I/O space registers.
For master requests to GX2 GLPCI.
Provides the possibility to virtualize NAND Flash
accesses when the IDE/Flash shared pins are in the ‘IDE
Position’. For the ‘Flash Position’, already dedicated IDE
descriptors can be used to virtualize.
Number
Port
1
2
3
4
5
6
7
GLIU
Descriptor Summary
Table 4-1. GLIU Port Connections
Port Connections
Device
GeodeLink PCI South Bridge (GLPCI_SB)
USB Controller #2 (USBC2)
ATA-5 Controller (ATAC)
Diverse Device (DD)
AC97 Audio Controller (ACC)
USB Controller #1 (USBC1)
GeodeLink Control Processor (GLCP)
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