User Manual

Protocol Analysis
R&S
®
Scope Rider RTH
175User Manual 1326.1578.02 ─ 08
Color, display element Description
Cyan frame header Write frame. Text indicates transfer direction (W = write) and address of the
frame (hex)
Yellow comb Address
Cyan comb Data bytes
Violet Acknowledge bit
Red Missing acknowledge bit, error in frame, insufficient frame (end of acquisi-
tion before decoding has been completed)
In "Protocol" mode, decoded data is shown in tabular form.
Table 8-2: Content of the protocol table for decoded I²C signal
Column Description
# Frame index
Frame Start Time of frame start
Address [hex] Hexadecimal value of the address
Address R/W Value of the R/W bit
Values 8 bit [format] Value of data byte. The data format is selected in the "Bus" menu.
State Overall state of the frame.
"Incomplete" indicates that the frame is not completely contained in the
acquisition. Change the time scale to get a longer acquisition.
Remote commands are described in Chapter 14.11.2.3, "I2C Decode Results",
on page 379.
8.3 SPI (Option R&S RTH-K1)
8.3.1 The SPI Protocol
A 4-channel instrument is required for full support of the SPI protocol.
The Serial Peripheral Interface SPI is used for communication with slow peripheral
devices, in particular, for transmission of data streams.
Main characteristics of SPI are:
●
Master-slave communication
●
No device addressing; The slave is accessed by a chip select, or slave select line.
●
No acknowledgement mechanism to confirm receipt of data
●
Duplex capability
SPI (Option R&S RTH-K1)