![background image](http://html.mh-extra.com/html/national-instruments/vxipc-850-series/vxipc-850-series_user-manual_709622031.webp)
Chapter 3 Configuration and Installation
VXIpc-850 Series User Manual
3 - 8
© National Instruments Corporation
EEPROM
The VXIpc-850 has an onboard EEPROM, which stores default register
values for the VXI circuitry. These values are loaded when you power
up the computer. These values read from the EEPROM tell the PCI
interface of 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 circuit using switch S2. 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 3-8 shows the
possible configurations for S2.
S2
S2
a. VXI Circuitry Loads Power-on
Defaults from EEPROM (Default)
b. Power-on Self Configuration
Circuit is Disabled
Figure 3-8. Power-On Self Configuration Status
The EEPROM is divided into two halves; one half is factory configured
and one half is user configurable. Use switch S9 to control the
operation of the EEPROM. The setting of this switch determines
whether the VXIpc -850 boots off the factory-configured half or 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 VXIpc -850 boots to an unusable state. In its default setting, the
VXIpc-850 boots off the user-configurable half.
Figure 3-9 shows the configuration settings for EEPROM operation.
S9
S9
a. Boot from User
Configuration (Default)
b. Boot from Protected
Configuration
Figure 3-9. SMB Trigger Input Termination