Table of Contents
Advertisement
iSBC® 608/618 MODULAR CARDCAGE & BACKPLANE
i.
Install iSBC boards into each cardcage.
Ensure that board placement
conforms to desired priority scheme (see Section 2-11).
Install I/O
connectors onto edge connectors.
2-11
PRIORITY RESOLUTION
If your system uses more than one Multibus master board, a priority reso-
lution scheme must be established to arbitrate Multibus requests.
The
iSBC 608 backplane implements a parallel priority resolution scheme by
using plug-in jumper connections (Figure 2-5)*
There are six different
priority schemes allowed, each requiring a different
jumper configur-
ation.
In each configuration, a particular board slot will have a dif-
ferent priority.
Table 2-5 lists the priority slots and the corres-
ponding required jumper configuration.
The factory default configuration
places the highest priority in slot JI, with each successive slot having
one level lower priority (see Table 2-5).
In systems where a n iSBC 618 expansion cardcage is attached to the base
unit, the base unit will have lower priority overall.
In this configur-
ation the master boards in the iSBC 608 base cardcage may gain control of
the Multibus lines only when no boards in the iSBC 618 cardcage are as-
serting the Bus Request (BREQ/ ) signal.
Remove jumper connection 23 - 2 4
on the iSBC 608 backplane to enable 16 slot resolution.
12 -
Advertisement
Table of Contents
