Datasheet

3−10
Table 3−3. Configuration via MS0 and MS1
MS0
MS1 MODE
0 0 CompactPCI hot-swap friendly
PCI Bus Power Management Interface Specification (Revision 1.1)
HS_SWITCH
/GPIO(3) functions as HS_SWITCH
0 1 CompactPCI hot-swap disabled
PCI Bus Power Management Interface Specification (Revision 1.1)
HS_SWITCH/GPIO(3) functions as GPIO(3)
1 X Intel™ compatible
No cPCI hot swap
PCI Bus Power Management Interface Specification (Revision 1.0)
3.14 CompactPCI Hot-Swap Support
The PCI2050B bridge is hot-swap friendly silicon that supports all of the hot-swap capable features, contains support
for software control, and integrates circuitry required by the PICMG CompactPCI Hot-Swap Specification. To be
hot-swap capable, the PCI2050B bridge supports the following:
• Compliance with PCI Local Bus Specification
• Tolerance of V
CC
from early power
• Asynchronous reset
• Tolerance of precharge voltage
• I/O buffers that meet modified V/I requirements
• Limited I/O terminal voltage at precharge voltage
• Hot-swap control and status programming via extended PCI capabilities linked list
• Hot-swap terminals: HS_ENUM
, HS_SWITCH, and HS_LED
cPCI hot-swap defines a process for installing and removing PCI boards without adversely affecting a running system.
The PCI2050B bridge provides this functionality such that it can be implemented on a board that can be removed
and inserted in a hot-swap system.
The PCI2050B bridge provides three terminals to support hot-swap when configured to be in hot-swap mode:
HS_ENUM
(output), HS_SWITCH (input), and HS_LED (output). The HS_ENUM output indicates to the system that
an insertion event occurred or that a removal event is about to occur. The HS_SWITCH
input indicates the state of
a board ejector handle, and the HS_LED output lights a blue LED to signal insertion- and removal-ready status.