Notes
PES16NT2 User Manual
7 - 1
April 15, 2008
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Chapter 7
NTB Upstream Port Failover
Introduction
The PES16NT2 supports an NTB upstream port failover mechanism that enables the construction of
fault tolerant systems.
The NTB upstream port failover usage model is illustrated in Figure 7.1. In this usage there is a primary
root and a secondary root. Both roots are active and may communicate using transactions flowing through
the NTB, mechanisms provided by the NTB for interprocessor communications, or an out-of-band commu-
nications channel. In normal mode, the primary root is responsible for configuring and managing the internal
PCIe hierarchy (i.e., the PCIe hierarchy consisting of upstream port A, P2P bridges, and the internal NTB
endpoint).
NTB upstream port failover enables the swapping of the upstream port (i.e., port A) with the NTB port
(i.e., port C). When a hardware or software failure is detected in the primary root, the PES16NT2 may be
directed to operate in a failover mode. In failure mode, the secondary root (i.e., the root associated with port
C) becomes the root responsible for configuring and managing the internal PCIe hierarchy and the primary
root becomes the root of the external NTB hierarchy.
Figure 7.1 NTB Upstream Port Failover Usage Model
The PES16NT2 NTB upstream port failover architecture is shown in Figure 7.2. The two main compo-
nents of this device are switch logic and a SerDes switch. The PES16NT2 switch logic implements a two
port non-transparent switch that does not support NTB upstream port failover. It consists of PCIe stacks, a
switch core and NTB logic. The SerDes switch enables SerDes lanes associated with port A and C to be
passed through unmodified or swapped.
In normal mode, the SerDes switch operates in a pass-through configuration. This connects the external
SerDes lanes associated with port A with the internal port A upstream port of the switch logic and the
SerDes lanes associated with port C with the internal port C NTB port. In failover mode, the SerDes switch
operates in a swapped configuration. This connects the SerDes lanes associated with port A to the internal
port C NTB port and the external SerDes lanes associated with port C to the internal port A upstream port.
In failover mode, the device associated with port C SerDes assumes all of the resources and responsi-
bilities of the internal port A upstream port and visa versa. This means that the root associated with port C
has direct access to all port A upstream port registers, receives internal PCIe hierarchy messages (e.g.,
error and INTx), and so on.
Primary
Port A
(Upstream Port)
Port C
(NTB Port)
PES16NT2
Root
Secondary
Root
(a) Normal Mode Operation
(b) Failover Mode Operation
Primary
Port A
(NTB Port)
Port C
(Upstream Port)
PES16NT2
Root
Secondary
Root
Содержание 89HPES16NT2
Страница 14: ...DT List of Figures PES16NT2 User Manual viii April 15 2008 Notes...
Страница 20: ...IDT Register List PES16NT2 User Manual xiv April 15 2008 Notes...
Страница 32: ...IDT PES16NT2 Device Overview PES16NT2 User Manual 1 12 April 15 2008 Notes...
Страница 44: ...IDT Clocking Reset and Initialization Clock Operation PES16NT2 User Manual 2 12 April 15 2008 Notes...
Страница 50: ...IDT Link Operation PES16NT2 User Manual 3 6 April 15 2008 Notes...
Страница 62: ...IDT Power Management PES16NT2 User Manual 5 4 April 15 2008 Notes...
Страница 78: ...IDT SMBus Interfaces PES16NT2 User Manual 6 16 April 15 2008 Notes...
Страница 83: ...IDT NTB Upstream Port Failover PES16NT2 User Manual 7 5 April 15 2008 Notes...
Страница 84: ...IDT NTB Upstream Port Failover PES16NT2 User Manual 7 6 April 15 2008 Notes...
Страница 130: ...IDT Transparent Mode Operation PES16NT2 User Manual 9 44 April 15 2008 Notes...
Страница 284: ...IDT Non Transparent Mode Operation PES16NT2 User Manual 10 154 April 15 2008 Notes...