©NationalInstruments Corporation 3-1 PXI-PCI8330 Series User Manual
3
Hardware Overview
Thischapter presents an overview of the hardware functions of your MXI-3
system,and explains the operation of each functional unit.

Functional Overview

The MXI-3 system is a PCI-PCI bridge that needs no software for normal
operation. When the desktop PC or the CompactPCI/PXI controller
powers on, the systemBIOS scans its local PCI bus for devices. When it
finds the primary interface of the MXI-3 card, it initiates configuration
cycles and searches for PCI devices on the secondary side.
Figure 3-1 showsthe basic architecture of the MXI-3 system. The MXI-3
cardinterfaces to the PCI bus with the National Instruments MXI-3 ASIC.
The ASIC convertsPCI transactions into a 20-bit wide parallel bus.
A parallelto s erial convertertransmits the 20-bit data as serial data at
1.5 Gbits/s. Ifyou are using copper cable,the system sends the serial data
through thecable as a differential electrical signal. If you are using
fiber-opticcable, the system converts the serial data to light using a
VCSELm odule.
On the other side of the system, the MXI-3 card receivesthe data, using
high-speedphotodetectors to convert light signals back to digital data in the
casewhere afiber-optic MXI-3 is used. A serial to parallel converter then
convertsthe digital serial data to the original 20-bit wide packets of data for
the MXI-3 ASIC. MXI-3 then recreates the PCItransaction with
appropriate modifications.