Kontron CPCI Generic backplane - Manual (Page 26)

General CPCI Backplane
Page 12 © 2002 PEP Modular Computers GmbH ID 24229, Rev. 01
3.5 Coding Keys
Figure 7: Board/Rack Coding
Keys
PEP Modular Computers Compact-PCI
systems present an advantage in the
form of a special combination of coding
keys. They ensure proper mating of
boards and backplanes in terms of volt-
age and function. For this purpose, two
different kinds of coding keys have
been devised, which are described in
the following.
Main Board Keying
Proper board installation is ensured by
the use of colored coding keys for 3.3V
(yellow) or 5V (blue) operation, thus
preventing incorrect installation of
adapter boards. This facility also pre-
vents confusion when hot-swapping
boards.
Additional Board Keying
The function of the additional board
coding key depends on the backplane.
Backplanes equipped with an H110
telephony connector are marked with a
red H110 key. Dual-PCI backplanes use
coding keys for 3.3V (yellow) or 5V
(blue) operation of the upper PCI bus.
AC/DC Keying
To ensure proper connection in terms of
AC/DC power, all
PEP Modular Com-
puters power supply units are provided
with special AC/DC coding keys.
The coding standard is not fully defined
at the moment of writing. It will be
implemented as soon as available.
Rack Keying
Boards must be fitted into a Compact-
PCI backplane in a certain order,
depending on whether they are bus
master boards or I/O boards. To this end, special asymmetrically shaped coding keys can be
used by the customer to ensure that the boards are inserted properly.
Main Board Coding Key
Rack Coding Keys
No key: universal signalling
Yellow: 3.3 V (NCR)
Blue: 5.0 V
Red
Additional Board Coding Key
Red: H110 present
No key: universal signalling P4
P1
PCI Connectors
Yellow: 3.3 V (NCR)
Blue: 5.0 V
P1 and P4