User manual

Protocol Analysis
R&S
®
Scope Rider RTH
128User Manual 1326.1578.02 ─ 04
Source : CS / Clock / MOSI / MISO
Set the input channels of the SPI lines.
If option R&S RTH-B1 is installed, digital channels can also be used as source.
Polarity
Selects whether the chip select signal is high active (high = 1) or low active (low = 1).
Slope
Selects if data are sampled on the rising or falling slope of the clock. The clock slope
marks the begin of a new bit.
Thresholds / Technology
Sets the threshold value for digitization of signals. If the signal value is higher than the
threshold, the signal state is high. Otherwise, the signal state is considered low.
You can select the threshold voltages for various types of integrated circuits in the
"Technology" list, or set a user-defined value for each line in "Thresholds".
Word Length
Sets the number of bits in a word. The maximum length is 32 bit.
Bit Order
Defines if the data of the words starts with MSB (most significant bit) or LSB (least sig-
nificant bit). The display of the decoded signal considers this setting, results are dis-
played in the specified order.
Frame Timeout
Sets the minimum idle time between two data frames. If the time interval between the
data frames is shorter, the words are part of the same frame. Within the timeout, the
data and clock lines are low. A new frame begins when the timeout has expired.
Timeout is only relevant if the bus has no chip select.
7.3.3 SPI Trigger Settings
Access: "Bus" menu > "Bus Protocol" = "SPI" > "Trigger"
SPI (Option R&S RTH-K1)