Chapter 3
Configuration and Default Settings
VXIpc 770/870B Series User Manual
3-6
ni.com
MITE EEPROM
Power-On Self Configuration
The VXIpc 770/870B Series has an onboard EEPROM, which stores
default register values for the VXI circuitry. These values are loaded when
you power up the computer. The values read from the EEPROM program
the PCI interface and the VXIbus registers so that the VXI interface is ready
to respond to Resource Manager accesses within the required 5 s of
SYSRST# deasserting.
You can disable this power-on self-configuration (POSC) circuit by
changing switch W2. Although this makes the VXI circuitry unusable,
it is sometimes helpful in debugging address and interrupt conflicts with
add-in boards. In general, however, you should leave switch S2 in its
factory-default setting. Figure 3-6 shows the possible configurations
for W2.
Figure 3-6.
Power-on Self Configuration Status
User/Factory Configuration
The EEPROM is divided into two halves—one half is factory configured
and one half is user configurable. Use jumper W1 to control the operation
of the EEPROM. The setting of this jumper determines whether the
VXIpc 770/870B Series boots off the factory-configured half or the
user-modified settings. In its default setting, the VXIpc 770/870B Series
boots off the user-configurable half.
This jumper is useful in the event that the user-configured half of the
EEPROM becomes corrupted in such a way that the VXIpc 770/870B
Series boots to an unusable state. By altering this jumper setting, you can
return to the factory configuration and get up and running again. Use the
procedure as described in the
section.
a. VXI Circuitry Loads Power-on
Defaults from EEPROM (Default)
b. Power-on Self Configuration
Circuit is Disabled
W2
W2
