2. PCI Interface
54
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
During the negation of HEALTHY#, PowerSpan II disables its output and bidirectional pins
(
except for
LED#) to avoid applying power to non-powered components on the card. The signals connected
between PowerSpan II and these non-powered components result in floating pins on PowerSpan II.
PowerSpan II uses HEALTHY# to inhibit the input receivers. An inhibited receiver has no static
current path between supply and ground that could be activated by a voltage level near the switching
point.
“Resets, Clocks and Power-up Options” on page 167
for more details on HEALTHY# and
PowerSpan II reset.
2.4.4
CompactPCI Hot Swap Card Insertion and Extraction
A CompactPCI board has a staggered pin arrangement (long/medium/short) to allow power and
ground, signal and a Board Inserted Indicator (BD_SEL#) to be connected and disconnected in stages.
A limited number of power and ground pins are long. The rest of the power, ground, and signal pins are
of medium length. BD_SEL# is a short pin. When BD_SEL# connects, the physical connection process
is complete.
2.4.4.1
CompactPCI Hot Swap Process
A CompactPCI Hot Swap board is divided into two power regions: Early Power and Back End Power.
Early Power is provided by the long pins on the CompactPCI connector. Back End Power is controlled
by a sequencer on the card. The sequencer begins to power the Back End of the card when the short
CompactPCI signal BD_SEL# engages on insertion, or when host software enables the process as in a
High Availability system.
, PowerSpan II is designed into a CompactPCI adapter card.
assumes the CompactPCI backplane is not in reset during the insertion and
extraction process. For example, PowerSpan II’s P1_RST# is negated.