CP690
Hotswap
ID 20955, Rev. 03
© 2002 PEP Modular Computers GmbH
Page 4 - 3
4.
Hotswap
4.1
Technical Background of CompactPCI Hotswap
In many modern application systems downtime is costly and/or unacceptable. Server applica-
tions, telecommunications networks and automated systems requiring continuous monitoring
call for a system design in which a single card can be inserted or extracted without affecting the
rest of the system. The ease with which a board may be removed and replaced is dependent
on the mechanical design (form factor), the possibility of deactivating the software drivers for
the board (operating system) and the possibilty of removing and inserting the board without dis-
turbing the signal quality on the bus.
CompactPCI hotswap is currently the most effective way to meet this need. Staggered pins on
the backplane guarantee controlled power sequencing of the board, while the signals ENUM,
BDSEL, HEALTHY and the hotswap control and status register bits may be used to control
board access from the software side.
4.1.1
Hotswap System
A hotswap system consists of a hotswap platform which comprises a hotswap backplane, the
system host (CPU) with hotswap features, cooling, power supplies etc. plus the boards to be
hotswapped. Hotswapping is not possible unless the operating system has the capability to en-
able and disable the board specific driver during normal operation.
