Protocol analysis
R&S
®
RTE
836User Manual 1326.1032.02 ─ 20
For a description of the display settings, see also Chapter 13.1.3, "Display",
on page 515.
The instrument captures and decodes the signal according to the standard definition
and the configuration settings.
The color-coding of the various protocol sections and errors simplifies the interpretation
of the visual display. The decode information condenses or expands, depending on the
horizontal scale. Various data formats are available to show the result values.
Examples
The example in Figure 13-102 shows a simulated USB full speed message. A Token
OUT packet has been decoded, followed by an ACK packet with an erroneous comple-
mentary PID value (PID Error). The next event is a PRE packet, then a DATA1 packet
with two bytes of data transmitted, and with a valid CRC16. The trigger instant is at the
PID of the DATA1 packet.
Figure 13-102: USB full speed protocol: decoded and binary signal, and decode results
green brackets [...] = start and end of packet
blue packet = packet ok
green packet = data packet ok
red packet = error condition
yellow = PID
dark blue = address
blue = endpoint
purple = CRC5/16
grey = payload data bytes
The example in Figure 13-103 shows a simulated USB high-speed message. A Token
SETUP packet has been decoded, which contains a CRC5 error. The next event is a
Token IN packet and an incomplete MDATA packet. Note that an incomplete packet is
also decoded, as long as sample data are available. In such a case, no error is shown,
USB (option R&S
RTE-K60)
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