Diagnosis Guide

SP Expansion I/O Unit

The POWER3 SMP High Node can optionally have one or more SP Expansion I/O Units attached to the node. An SP Expansion I/O Unit is normally cabled to the node in a loop (with up to two expansion units per loop) which returns to the node. This creates a redundant data path from the expansion unit to the node.

An LCD value of 203w0xyz indicates a cabling configuration between the node and the SP Expansion I/O Unit which does not result in a complete loop. In this LCD, the w is the expansion unit loop number, the x is always 0, the y indicates the expansion I/O port number on the node's system rack, and the z can have the following values:

z=0

Incorrectly cabled SP Expansion I/O Unit configuration

z=B

A missing return link from the SP Expansion I/O Unit to the node's system rack

z=C

A missing cable between two SP Expansion I/O Units

z=D

A BIST (built-in self test) failure in the SP Expansion I/O Unit

z=E

An SP Expansion I/O Unit was found connected to port 1, 3, or 5 with no return to the node's system rack, and no SP Expansion I/O unit was found connected to port 2, 4, or 6 (respectively).

In this case, the expansion unit connected to port 1, 3, or 5 is removed from the configuration since the cause of the error and the proper location of the expansion unit cannot be determined.