2. PCI Interface
53
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
2.4
CompactPCI Hot Swap Silicon Support
CompactPCI’s Hot Swap Specification
defines the process for installing and removing adapter boards
without adversely affecting a running system. It provides a programmatic access to Hot Swap services.
This enables system re-configuration and fault recovery to take place with no system down time and
minimum operator interaction.
PowerSpan II is compliant with the
CompactPCI’s Hot Swap Specification, Revision 2.0
and is a
Hot
Swap Silicon device. Hot Swap Silicon support includes the following:
•
Open drain output pin ENUM# is used to indicate Hot Swap insertion and extraction events.
•
5V tolerant input pin ES for sensing the state of the ejector switch used to insert or extract a
CompactPCI board.
•
5V tolerant open drain output pin LED# for controlling the blue Light Emitting (LED) required to
indicate status of the software connection process.
For the different levels of Hot Swap support, refer to the
CompactPCI Hot Swap Specification
.
To simplify the design of CompactPCI Hot Swap adapter cards, PowerSpan II has additional support.
This support includes:
•
A 5V tolerant input pin HEALTHY# for sensing the status of the Back End power on the card.
•
An input pin P1_64EN# that enables Hot Swap adapter cards to sense the presence of a 64-bit PCI
backplane.
2.4.1
LED Support
The LED can be controlled by hardware and software. PowerSpan II drives the LED# signal low to
turn on the LED during the Physical and Hardware Connection process (when HEALTHY# is
negated). A blue LED with an internal resistor can be directly connected between the 5V rail and the
LED# signal. Software controls the LED by setting the LED On/Off (LOO) bit in the
PCI Hot Swap Control and Status Register” on page 264
2.4.2
ES Input
The
CompactPCI Hot Swap Specification
defines a switch located in the ejector handle that indicates to
PowerSpan II if the ejector handle is open or closed. A low value on ES input indicates that the ejector
latch is open. A high value on ES indicates that the ejector latch is closed and is in operation mode.
2.4.3
HEALTHY# Signal
PowerSpan II manages the electrical board level issues involved in the Hot Swap process with the
HEALTHY# signal. The negation of HEALTHY# indicates only some of the components on the Hot
Swap card are powered. To operate in this environment and minimize long term reliability issues, the
HEALTHY# signal controls the electrical behavior of PowerSpan II I/O buffers.