Protocol analysis
R&S
®
RTE
772User Manual 1326.1032.02 ─ 20
"Idle low"
The base value of the clock is "0"; after an idle period, the data signal
starts with a low-to-high transition.
"Idle high"
The base value of the clock is "1"; after an idle period, the data signal
starts with a high-to-low transition.
Remote command:
BUS<m>:CMSB:NRZ:IDLPolarity on page 1737
Clock Polarity (NRZ Clocked)
Defines the polarity of the custom serial bus clock signal (only available for the coding
standard "NRZ Clocked"). The available settings are:
"Idle low"
The base value of the clock is "0".
"Idle high"
The base value of the clock is "1".
Remote command:
BUS<m>:CMSB:NRZ:CPOLarity on page 1737
Clock Phase (Manchester)
Defines the phase of the custom serial bus clock signal for the Manchester coding
standards. The available settings are:
"Auto Detect"
Lets the decoder automatically select the method ("First Edge" or
"Second Edge") for detecting the clock phase.
"First Edge"
●
At "Idle" = "low": data are captured on the clock's rising edge
(low-to-high transition) and propagated on a falling edge.
●
At "Idle" = "high": data are captured on the clock's falling edge
(high-to-low transition) and propagated on a rising edge.
"Second Edge"
●
At "Idle" = "low": data are captured on the clock's falling edge
(high-to-low transition) and propagated on a rising edge.
●
At "Idle" = "high": data are captured on the clock's rising edge
(low-to-high transition) and propagated on a falling edge.
Note: The requirement to specify "First Edge" or "Second Edge" (or
let the decoder decide) has the following background: In Manchester
coding, an edge is always a transition from high to low (0) or from low
to high (1). However, if the signal comes from the idle state, this
implies that right before the first valid edge, there is always an over-
head transition from idle to high or from idle to low. Some standards
may regard this as a valid transition. To avoid a potentially ambiguous
situation, a decision has to be made if the first edge is indeed only
some overhead transition ‐ or a transition that needs to be sampled.
For more details on edge conditions, see Chapter 13.14.1.1, "Special
features of Manchester coding", on page 767.
Remote command:
BUS<m>:CMSB:MANChester:CPHase on page 1736
Clock Phase (NRZ Clocked)
Defines the phase of the custom serial bus clock signal for the coding standard "NRZ
Clocked", depending on "Clock Polarity". The available settings are:
Custom: Manchester / NRZ (option R&S
RTE-K50)M
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