Chapter 4 VME-MXI-2 Configuration and Installation
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National Instruments Corporation 4-7 VXI/VME-PCI802 2 for Sola ris
Configuration EEPROM
The VME-MXI-2 has an onboard EEPROM, which stores default
register values that are loaded at power -o n. Th e EE PRO M is divi ded
into two halves—a factory-configuration half, and a user-configuration
half. Both halves were factory configured with the same configuration
values so you can modify the user-configurable half, while the fac tory-
configured half stores a back-up of the default user settings.
Use switches 1 and 2 of the four-position switch at location U21 to
control the operation of the EEPROM. The Restore Factory
Configuration switch (switch 1) causes the VME-MXI-2 to boot off the
factory-configured half instead of the user-modified settings. This is
useful in the event that the user-configured half of the EEPROM
becomes corrupted in such a way that the VME-MXI-2 boots to an
unusable state.
The Change Factory Configuration switch (switch 2 of U21) lets you
change the factory-default configuration settings by permitting writes
to the factory settings section of the EEPROM. This switch serves as a
safety measure and should not be needed under normal circumstances.
When this switch is off (its default setting) the factory configuration of
the EEPROM is protected so any writes to the factory area will be
ignored. The factory area is protected regardless of the setting of
switch 1 of U21.
Figure 4-5 shows the configuration settings for EEPROM operation.
The settings of switches 3 and 4 have no effect on EEPROM
configuration.