Rohde & Schwarz RTE Series - Page 641

Protocol analysis
R&S
®
RTE
641User Manual 1326.1032.02 ─ 20
"I2S Standard"
Inter-IC sound standard audio format.
It uses the SCLK, WS and SDATA lines. The first byte of the audio
word is delayed one clock period from the leading edge of the word
select pulse.
"Left justified"
The left-justified data format uses the same lines as I²S standard. The
first byte of the audio word is aligned with the leading edge of the
word select pulse, or left justified within the frame. The format is
word-length independent.
"Right justified"
The right-justified data format is similar to the left-justified, but the last
byte of the last word in the frame is aligned with the trailing edge of
the word select pulse, or right-aligned within the frame. This format is
not word-length independent.
"TDM"
The Time Division Multiplexed audio format is not standardized and
provides high flexibility for transfer of up to 8 audio data channels on
one line. Instead of words select, it uses frame synchronization pul-
ses to identify the beginning of a frame. On the data line, channel
blocks of a defined length are transmitted. Each block contains an
audio word followed by several zero bits to complete the block.
Remote command:
BUS<m>:I2S:AVARiant on page 1592
SCLK
Selects the source of the clock line.
Usually, the source is one of the analog channels. Reference and math waveforms are
available as source if the trigger source is one of the analog channels but not the serial
bus.
Do not combine a reference waveform with channel or math waveform because the
time correlation of these waveforms might differ.
Alternatively, digital channels can be used if MSO option R&S RTE-B1 is installed. Dig-
ital and analog channels cannot be used at the same time.
For triggering on a serial bus, analog or digital channel sources are required.
Remote command:
BUS<m>:I2S:CLOCk:SOURce on page 1592
SCLK Polarity
Sets th polarity of the clock signal, that is the edge at which the instrument samples the
data on the data line. Usually, the rising edge is used. The R&S RTE can also analyze
the converse setup.
Remote command:
BUS<m>:I2S:CLOCk:POLarity on page 1593
WS / FSYNC
Selects the source of the word select line for I²S standard, left- and right-justified data
formats, or the source of the frame synchronization pulse for TDM audio signals. The
same waveforms as for SCLK are available, and the same restrictions are applied.
Audio signals (option R&S
RTE-K5)