R&S RTO6, User Manual

Page: 494 / 2677

Protocol analysis
R&S
®
RTO6
494 User Manual 1801.6687.02 ─ 05
"Overwrite mode": If disabled, the data behind the new digit is shifted to the right. Bit
groups are rearranged automatically.
Format-specific information:
●
Unsigned: Decimal data format without sign. It is available for I²C, SPI, UART,
CAN, LIN and FlexRay protocols. If you enter a decimal number that is too large for
the defined bit group, the number is truncated and a message appears. X (do not
care) in the decimal column sets all binary digits of the bit group to X.
●
Signed: Signed decimal format, available for audio protocols. The first bit repre-
sents the sign. You can use the 2's complement or 1's complement format.
●
Binary: 0, 1 and X (do not care) is allowed.
●
Hex: most common format in the right column.
●
Octal: Each digit represents 3 bit.
●
ASCII: In the ASCII column, "X" is the character X. The binary X (do not care) is
not allowed. If an X is included in the binary value in the left column, the ASCII col-
umn displays "§" to indicate that the value is not defined.
Where applicable, frequently used values are provided in a "Predefined values" list
below the pattern table, for example, reserved end words of data packets in the UART
protocol.
13.2 I²C (option R&S RTO6-K510)
The Inter-Integrated Circuit is a simple, low-bandwidth, low-speed protocol used for
communication between on-board devices.
● The I²C protocol .................................................................................................... 494
● I²C configuration ....................................................................................................496
● I²C trigger .............................................................................................................. 499
● I²C decode results .................................................................................................505
● Search on decoded I²C data ................................................................................. 506
13.2.1 The I²C protocol
This chapter provides an overview of protocol characteristics, data format, address
types and trigger possibilities. For detailed information, read the "I2C-bus specification
and user manual" available on the NXP manuals webpage at
http://www.nxp.com/ .
I²C characteristics
Main characteristics of I²C are:
●
Two-wire design: serial clock (SCL) and serial data (SDA) lines
●
Master-slave communication: the master generates the clock and addresses the
slaves. Slaves receive the address and the clock. Both master and slaves can
transmit and receive data.
I²C (option R&S RTO6-K510)