
IDT Usage Models
PES32NT24xG2 User Manual
26 - 6
January 30, 2013
Notes
Figure 26.4 PES16NT8BG2 with Two Partitions Configured via a Switch Manager Root Complex
Description
As dictated by the switch mode, all ports and partitions are initially in unattached mode (see section
–
Ports connected to the root-complex or to another switch’s downstream port on the system board
link train normally.
–
Ports connected to endpoint devices or to another switch’s upstream port on the system board
form a crosslink.
1
–
Ports respond to all received type 0 configuration request with configuration-request-retry-
completion, except for accesses to the global space access registers in function 0 of the port (i.e.,
GASAADDR and GASADATA).
• This in essence fences-off non switch manager roots from enumerating the switch until it is prop-
erly configured.
–
The switch manager root (i.e., RC0, connected to port 0) has a customized BIOS to configure the
switch. The other root complex (RC1 connected to port 12) is operating under a normal BIOS.
• The customized BIOS starts by configuring switch partitions as described below, and then
proceeds to enumeration.
–
As indicated in section Partition Resets on page 3-11, the switch manager has 1 second to
configure the switch after the deassertion of the switch’s fundamental reset signal (i.e., PERSTN)
on the system board. This time limit represents the time during which RC1 won’t give up on
enumeration after receiving configuration-request-retry-completions.
Within this time, the switch manager performs the switch configuration as follows:
1. Waits for the data link of the root port to be DL_Up. Under normal circumstances this is completed
within the first millisecond after de-assertion of PERSTN.
2. Issues type 0 configuration requests to the switch’s port 0, targeting the GASAADDR and GASA-
DATA registers.
Through these registers, the switch manager is able to indirectly access the switch’s global
1.
A crosslink is only formed if the link-partner supports crosslink. Otherwise, the crosslink formation fails until the
unattached port’s mode is modified to a downstream switch port mode.
P0
(P2P)
P8
(P2P)
P10
(P2P)
P12
(P2P)
P16
(P2P)
P18
(P2P)
Partition 0
Partition 1
Switch
RC0
(Switch Manager)
RC1
EP
EP
EP
EP
Switch Manager configures the
switch through the global
address space registers
(GASAADDR & GASADATA)
in this P2P function
Summary of Contents for PCI Express 89HPES32NT24xG2
Page 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Page 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Page 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Page 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Page 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Page 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Page 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Page 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Page 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Page 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Page 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Page 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Page 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Page 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Page 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Page 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Page 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Page 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Page 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Page 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Page 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
Page 744: ...IDT Usage Models PES32NT24xG2 User Manual 26 34 January 30 2013 Notes...