Vme Overview - HP 748 Owner's Manual

VME Overview

VME (Versa Module Eurocard) cards use a VME bus protocol which allows
various kinds of microprocessors to communicate with one another. The
protocol is microprocessor independent, implements a reliable mechanical
standard, and allows independent vendors to build compatible products.
One feature of VME is that multiple CPUs can be configured into the same
VME backplane. Each one functions as a completely separate processor, but
they all must be able to access address space that may or may not exist on
the local computer board. The address space that one CPU needs to access
may be on a separate memory card or on an entirely different CPU board.
The VME standard allows two board sizes:
• Half height or 3U boards. These boards connect to the VME backplane
utilizing only one of the two backplane connectors.
• Full height or 6U boards. These boards connect to the VME backplane uti-
lizing both of the backplane connectors.
3U size boards are often provided with either 3U size or 6U size cover plates
allowing them to be placed in either a half height or full height chassis.
The Model 748 provides eight full-height VME slots. The VME System
Controller occupies slots 1 and 2, leaving slots 3 through 8 available for use.
In the backplane, slot 3 is the lowermost slot and slot 8 is the uppermost.
The vendor of your VME card should have provided installation configura-
tion settings for the card, for your particular application. These usually allow
the card to be installed in one of several default locations.
All VME cards require kernel drivers. The HP-UX kernel provides a set of
services in the fileset VME-SERV which allows the user-provided kernel
drivers access to VME space. You can use SAM to ensure that the vme2
driver is in your HP-UX kernel.
Your vendor should have provided you with the necessary files and instruc-
tions for linking the driver for your card into the HP-UX kernel. Documenta-
tion for creating these drivers for HP-UX 9.0x is contained in the HP-UX
VME Card Installation
VME Overview
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