Atec Tektronix-DPO4104 - Manual (Page 3)

Digital Phosphor Oscilloscopes
DPO4000 Series
Oscilloscope • www.tektronix.com/oscilloscopes 3
Serial Triggering and Analysis
One of the most common applications
requiring long record length is serial data
analysis in embedded system design.
Embedded systems are literally every-
where. They can contain many different
types of devices including microprocessors,
microcontrollers, DSPs, RAM, EPROMs,
FPGAs, A/Ds, D/As and I/O. These various
devices have traditionally communicated
with each other and the outside world
using wide parallel buses. Today, however,
more and more embedded systems are
replacing these wide parallel buses with
serial buses due to less board space re-
quired, fewer pins, lower power, embedded
clocks, differential signaling for better
noise immunity, and most importantly,
lower cost. In addition, there’s a large
supply of off-the-shelf building block
components from reputable manufacturers,
enabling rapid design development. While
serial buses have a large number of bene-
fits, they also present significant challenges
that their predecessors (parallel buses) did
not face. They make debugging bus and
system problems more difficult, it’s harder
to isolate events of interest and it’s more
difficult to interpret what is displayed on
the oscilloscope screen. The DPO4000
Series addresses these problems and
represents the ultimate tool for engineers
working with low-speed serial buses such
as I 2 C, SPI and CAN.
Bus Display – Provides a higher level
combined view of the individual signals
(clock, data, chip enable, etc.) that make up
your bus, making it easy to identify where
packets begin and end and identifying
sub-packet components such as address,
data, identifier, CRC, etc.
Serial Triggering – Trigger on packet
content such as start of packet, specific
addresses, specific data content, unique
identifiers, etc., on popular low-speed
serial interfaces such as I 2 C, SPI and CAN.
Bus Decoding – Tired of having to visually
inspect the waveform to count clocks,
determine if each bit is a 1 or a 0, combine
bits into bytes and determine the hex
value? Let the oscilloscope do it for you!
Once you’ve set up a bus, the oscilloscope
will decode each packet on the bus, and
display the value in either hex or binary in
the bus waveform.
Packet Decode Table – In addition to
seeing decoded packet data on the bus
waveform itself, you can view all captured
packets in a tabular view much like you
would see on a logic analyzer. Packets
are listed consecutively with columns for
each component (Address, Data, etc.).
Triggering on specific data packet going across an I2C bus. Yellow waveform is data, blue waveform
is clock. Bus waveform provides decoded packet content including Start, Address, Read/Write, Data,
Missing Ack and Stop.