
IDT Hot-Plug and Hot-Swap
PES32NT24xG2 User Manual
11 - 7
January 30, 2013
Notes
possible to meet a profile’s power level invalid to reset asserted timing specification (i.e., PxPWRGDN to
PxRSTN). Systems that require a shorter time interval may implement this functionality external to the
switch.
Hot-Plug Events
The hot-plug controller associated with a downstream switch port slot may generate an interrupt or
wakeup event.
Note: Interrupts and wakeup events only affect the partition with which the downstream switch port is
associated.
Hot-plug interrupts are enabled when the Hot Plug Interrupt Enable (HPIE) bit is set in the corre-
sponding port’s PCI Express Slot Control (PCIESCTL) register.
The following bits, when set in the PCI Express Slot Status (PCIESSTS) register, generate an interrupt if
not masked by the corresponding bit in the PCI Express Slot Control (PCIESCTL) register or by the HPIE
bit: the Attention Button Pressed (ABP), Power Fault Detected (PFD), MRL Sensor Changed (MRLSC),
Presence Detected Changed (PDC), Command Completed (CC), and Data Link Layer Active State Change
(DLLLASC).
When an unmasked hot-plug interrupt is generated, the action taken is determined by the MSI Enable
(EN) bit in the MSI Capability (MSICAP) register and the Interrupt Disable (INTXD) bit in the downstream
switch port’s PCI Command (PCICMD) register. Refer to section Interrupts on page 10-4 for details.
When the downstream switch port is in the D3
hot
state, then the hot-plug controller generates a wakeup
event using a PM_PME message instead of an interrupt when the following conditions are satisfied.
–
The status bit for an enabled hot-plug event listed below transitions from not set to set.
• Attention button pressed
• Power fault detected
• MRL sensor changed
• Presence detect changed
• Command completed event
• Data link layer state change event
–
The PME Enable (PMEE) bit in the downstream switch port’s PCI Power Management Control and
Status (PMCSR) is set.
It is not required that the Hot Plug Interrupt Enable (HPIE) bit be set in the corresponding port’s PCI
Express Slot Control (PCIESCTL) register in order to generate a wakeup event using a PM_PME message.
Software may clear the HPIE bit to disable interrupt generation while keeping wakeup event generation
enabled. If a hot-plug event occurs while a downstream switch port is in D3
hot
and the corresponding inter-
rupt is enabled, the port will generate an interrupt if the corresponding event’s status bit is set in the
PCIESCTL is set and the state of the port is transitioned from D3
hot
to D0 without a reset.
Legacy System Hot-Plug Support
Some systems require support for operating systems that lack PCI Express hot-plug support. The
PES32NT24xG2 supports these systems by providing a General Purpose Event (GPEN) output as a GPIO
alternate function that can be used instead of the INTx, MSI, and PME mechanisms defined by PCI Express
hot-plug.
Note: Because the PES32NT24xG2 only supports a single GPEN output signal, the GPEN signal is
associated with partition 0. Partitions other than partition 0 do not support this feature.
Associated with each downstream switch port’s hot-plug controller is a bit in the General Purpose Event
Control (GPECTL) register. When this bit is set, the corresponding PCI Express Base Specification 2.1 hot-
plug event notification mechanisms are disabled for that port and INTx, MSI, and PME events will not be
generated by that port due to hot-plug events. Instead, hot-plug events are signaled through assertion of
the GPEN signal.
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...