
IDT Usage Models
PES32NT24xG2 User Manual
26 - 22
January 30, 2013
Notes
• The FEN field in the SWPART4CTL and SWPORT6CTL registers is set to 0x1.
–
Ports 4 and 6 are configured to respond to primary and secondary failover events by programming
fields in the SWPORT4FCTL and SWPORT6FCTL registers as follows:
• SFMODE = 0x1 (i.e., secondary failover mode is set to downstream port)
• SFSWPART = 0x1 (i.e., secondary failover partition is set to partition 1)
• SFDEVNUM = 0x4 (for port 0) and 0x6 (for port 1)
• PFMODE = 0x2 (i.e., primary failover mode is set to downstream port)
• PFSWPART = 0x0 (i.e., primary failover partition is set to partition 0)
• PFDEVNUM = 0x4 (for port 4) and 0x6 (for port 6)
–
In addition, ports 4 and 6 are configured to be reset during the failover operation by programming
the Operating Mode Change Action (OMA) field in the SWPORT4CTL and SWPORT6CTL regis-
ters to a value of 0x1.
• Resetting these ports is desired in this scenario so that when the failover operation takes place,
the root complex to which these ports are assigned finds the ports in a non configured state.
• In addition, resetting the ports causes the port’s links to be retrained from the Detect state,
thereby causing a hot reset to any devices downstream.
–
The failover capability 0 is enabled to respond to a failover signal trigger by setting the FSIGPOL
and FSIGEN bits in the FCAP0CTL register.
–
Since the failover signal trigger associated with failover capability 0 is an alternate function of
GPIO[4], this GPIO is configured for alternate function operation by programming GPIOAFSEL
and GPIOFUNC registers appropriately. Refer to Chapter 13, General Purpose I/O for details.
–
At this point the failover mechanism is armed. A failover is triggered when the platform asserts the
failover signal trigger. The failover signal has the polarity programmed in the FSIGPOL field in the
FCAP0CTL register.
After EEPROM loading completes, the switch exits quasi-reset mode and the roots can proceed to
configure the device.
–
The BIOS executing in the active root will find a fully configured switch with one upstream port and
two downstream ports. The two downstream ports have device numbers 4 and 6.
–
The BIOS executing in the passive root will find that the link that connects the root port to the
switch’s port 8 is down. As a result, no PCI Express hierarchy is found below that root port.
If the platform asserts the failover signal trigger (e.g., after detecting a problem with the primary root
complex), a failover event is automatically executed by the switch. The failover event causes the following
actions (in the order listed below
1
):
1. Ports 4 and 6 are migrated from partition 0 to partition 1. During the migration process, the ports are
reset.
This causes the downstream links to retrain from the Detect state, thereby causing a hot reset
to the endpoint devices.
2. Partition 0 becomes disabled and partition 1 becomes active.
When partition 0 becomes disabled, port 0 becomes disabled.
When partition 1 becomes active, port 8 becomes active as an upstream switch port in that par-
tition.
Figure 26.13 shows the system configuration after the failover event.
1.
Refer to section Partition Reconfiguration and Failover on page 5-21 for details on the order of reconfiguration
actions during failover.
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...