
IDT Usage Models
PES32NT24xG2 User Manual
26 - 19
January 30, 2013
Notes
Figure 26.11 Target System Configuration
The root-complex connected to the transparent switch completes enumeration. This root-complex views
each processor node as an endpoint device with a single function (i.e., the NT function). Enumeration soft-
ware assigns a memory region to the BAR aperture(s) associated with the NT function.
In parallel with the previous step, the BIOS in each processor node proceeds to enumerate its PCI
Express hierarchy. Enumeration software detects a hierarchy with a multi-function device containing two
endpoint functions (i.e., NT function and DMA function) connected to a root-port. Enumeration software
assigns memory regions to the BAR apertures associated with the NT function and DMA functions.
–
An NT software driver will be associated with the NT function.
–
A DMA software driver will be associated with the DMA function.
Software executing in the processing nodes and the transparent switch manager both use the NT
messaging capability to exchange messages and coordinate the programming of the NTB windows used
for communication.
–
NTB windows for communication between the transparent switch’s manager and any of the peer
processors are configured.
–
NTB windows for direct communication between the peer processors are configured.
The DMA function in the switch will be used for high-speed data transfer data among peer processors.
The DMA offloads the CPU in each processing node from performing the data transfer. The DMA software
driver operates by managing descriptor lists, controlling the DMA function channels, and processing DMA
interrupts.
Software that wishes to use DMA services can issue a system call to the DMA driver to perform the
desired data transfer. In particular, software layers in charge of multiprocessor communication need only
issue a call to the DMA driver with system addresses that map to the appropriate NTB windows. The DMA
driver builds the descriptor lists and programs the DMA function appropriately. The DMA hardware performs
the transfer and issues an interrupt when the transfer completes.
P2P
P2P
P2P
P2P
RC
RC
NT
P4
( NT)
DMA
Port 0
Switch
NT
P4
(NT)
DMA
Port 0
Switch
NT
P4
(NT)
DMA
Port 0
Switch
RC
RC
Processor
Node
Processor
Node
Processor
Node
Содержание PCI Express 89HPES32NT24xG2
Страница 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Страница 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Страница 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Страница 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Страница 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Страница 124: ...IDT Switch Partition and Port Configuration PES32NT24xG2 User Manual 5 24 January 30 2013 Notes...
Страница 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Страница 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Страница 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Страница 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Страница 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Страница 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Страница 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Страница 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Страница 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Страница 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Страница 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Страница 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Страница 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Страница 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Страница 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Страница 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
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