Datasheet

Intel
®
Xeon
®
Processor C5500/C3500 Series
February 2010 Datasheet, Volume 1
Order Number: 323103-001 413
Reliability, Availability, Serviceability (RAS)
11.7.2.3 Virtual Pin Ports (VPP)
The Intel
®
Xeon
®
processor C5500/C3500 series IIO contains a virtual pin port (VPP) that serially
shifts in and out the sideband PCIe hot plug signals. VPP is a 100 KHz SMBus interface that connects
to a variable number of serial to parallel I/O ports.
Example: the Phillips* PCA9555. Each PCA9555 supports 16 GPIOs structured as two 8-bit ports, with
each GPIO configurable as an input or an output. Reading or writing to the PCA9555 component with
a specific command value reads or writes the GPIOs or configures the GPIOs to be either input or
output. The IIO supports up to five PCIe hot plug ports through the VPP interface with maximum of
two PCA9555 populated.
Figure 82. GPE Message Generation Logic at each PCI Express Port for PCI Express Hot
Plug
C
X
C
C
C
C
Slot Status Register
Command
Completed
Attention Button
Pressed
Power Fault
Detected
MRL Sensor
Changed
Presence Detect
Changed
Slot Control Register
X
X
X
X
X
Command
Completed Enable
Attention Button
Pressed Enable
Power Fault
Detected Enable
MRL Sensor
Changed Enable
Presence Detect
Changed Enable
HP Interrupt
Enable
Enable ACPI Mode for Hotplug
MISCCTRLSTS[3]
Assert
Deassert
C
X
Data Link Layer State
Changed
Data Link Layer State
Changed Enable