
IDT Upstream Port Failover
PES34H16 User Manual
2 - 2
October 30, 2008
Notes
When the PES34H16 is configured to operate in an upstream port failover switch mode, port 2 is always
disabled. If the upstream port is configured to operate in x8 merged mode, then both ports two and three
are disabled. The behavior of a disabled port is described in the section entitled section Disabled Ports on
page 1-16.
Upstream port resources (e.g., link status control LED outputs) are always associated with port 0
regardless of the external PES34H16 port associated with the upstream port. The PES34H16 consists of
eight bifurcating PCIe stacks. A PES34H16 stack may be configured to operate as two x4 ports (bifurcated
mode) or as one x8 port (merged mode).
Upstream port failover is supported in both x4 and x8 upstream port modes. However, both ports 0 and
2 must be configured to operate in the same mode (i.e., if port 0 is configured to operate in x8 merged
mode, then port 2 must also be configured to operate in x8 merged mode). Configuring ports 0 and 2 to
operate in different modes produces an undefined behavior.
If the PES34H16 is configured to operate in an upstream failover mode and the upstream port is config-
ured to operate in x4 bifurcated mode, then ports 1 and 3 operate as normal. While upstream port failover
mode disables port 2, in bifurcated mode it has no effect on the operation of ports 1 and 3.
If the PES34H16 is configured to operate in an upstream failover mode and the upstream port is config-
ured to operate in x8 merged mode, then ports 1, 2, and 3 are disabled. The behavior of a disabled port is
described in section Disabled Ports on page 1-16. x8 merged mode and x4 bifurcated mode data paths for
upstream port failover are illustrated in Figure 2.2. The red lines show the upstream port data path. The
green lines show the data paths for other ports.
Figure 2.2 Upstream Failover Mode Data Configurations
Failover
An upstream port failover may be initiated statically through a fundamental reset or dynamically while
the system is running.
Stack 0
SerDes
Port 0
SerDes
Port 1
SerDes
Port 2
SerDes
Port 3
Stack 1
(a) x8 Upstream Failover Mode with
Port 0 Selected
Stack 0
SerDes
Port 0
SerDes
Port 1
SerDes
Port 2
SerDes
Port 3
Stack 1
(b) x8 Upstream Failover Mode with
Port 2 Selected
Stack 0
SerDes
Port 0
SerDes
Port 1
SerDes
Port 2
SerDes
Port 3
Stack 1
(c) x4 Upstream Failover Mode with
Port 0 Selected
Stack 0
SerDes
Port 0
SerDes
Port 1
SerDes
Port 2
SerDes
Port 3
Stack 1
(d) x4 Upstream Failover Mode with
Port 2 Selected
Summary of Contents for 89HPES34H16
Page 10: ...IDT Table of Contents PES34H16 User Manual iv October 30 2008 Notes...
Page 12: ...IDT List of Tables PES34H16 User Manual vi October 30 2008 Notes...
Page 18: ...IDT Register List PES34H16 User Manual xii October 30 2008 Notes...
Page 40: ...IDT Upstream Port Failover PES34H16 User Manual 2 6 October 30 2008 Notes...
Page 86: ...IDT Power Management PES34H16 User Manual 7 4 October 30 2008 Notes...
Page 172: ...IDT Configuration Registers PES34H16 User Manual 9 80 October 30 2008 Notes...