Serial bus analysis
R&S
®
RTA4000
264
User Manual 1335.7898.02 ─ 08
Remote command:
CHANnel<m>:THReshold:FINDlevel
Word Size
Sets the word length (or symbol size), which is the number of bits in a message. The
maximum word length is 32 bit.
You can also define the bit order, which determines if the data of the messages starts
with "MSB" (most significant bit) or "LSB" (least significant bit).
Remote command:
Idle Time
Sets the burst idle time, during which the data and clock lines are low. Only available in
the "SPI (no CS)" setup.
A new frame begins when the idle time has expired and the clock line has been inac-
tive during that time. If the time interval between the data words is shorter than the idle
time, the words are part of the same frame.
Remote command:
13.2.3
SPI trigger
Before you set up the trigger, make sure that the bus is configured correctly. See
Chapter 13.2.2, "SPI configuration"
To trigger on SPI signals:
1. Press the [Protocol] key in the Analysis area of the front panel.
2. Select the bus that is configured for SPI.
3. Select "Trigger".
This selection has several effects:
● Enables decoding, if necessary.
● Sets the "Trigger Type" to "Serial Bus" and the trigger source to the selected
bus.
● Displays the "SPI Trigger" condition in the dialog box, below the protocol setup.
4. Check the "Source". Change it if necessary.
5. At "SPI Trigger", select the required trigger type:
● "Frame Start": beginning of the message
● "Frame End": end of the message
SPI bus (option R&S
RTA-K1)
