Physical Layer Testing of PCI-Express Signals Using Consecutive Bits

Recent detection schemes use clock- less over sampling techniques in which the receiver compares bits sampled at several times the bit rate.
Physical Layer Testing of PCI-Express Signals
Using Consecutive Bits
LeCroy Corporation Booth 600 Intel Developers Forum Press and Analyst
Dr. Michael Lauterbach, Director, Product Management

Introduction
Traditionally, serial data signals such as Fibrechannel and Infiniband have used recovered clocks in
their receiver circuits to detect the incoming data bits. More recent detection schemes use clock-less
over sampling techniques in which the receiver compares bits sampled at several times the bit rate.
The bits from each phase of the over sampled signal are then polled to determine the correct bit
values. The development of the serial ATA standard and now PCI-Express, account for these different
detection schemes through specification of the use of consecutive UI in the measurement of bo