Datasheet

www.tektronix.com/bench 3
Digital Debugging Tips Using a Mixed Signal or Mixed Domain Oscilloscope
Color-Coded Digital Waveform Display
Digital timing waveforms look very similar to analog waveforms
except only logic highs and lows are shown. Timing acquisition
analysis often focuses on determining logic values at specific
points in time and measuring the time between edge transitions
on one or more waveforms. To make analysis easier, the
Tektronix MSO Series shows logic lows as blue and logic
highs as green on the digital waveforms, allowing you to see
the logic value even if a transition is not visible. The waveform
label color also matches the probe color-coding to make it
easier to see which signal corresponds to which test point, as
shown in Figure 4.
The digital timing waveforms can be grouped to create a
bus. One digital signal is defined as the least significant bit
and the other digital signals represent the other bits of the
binary number up to the most significant bit. The MSO will
then decode the bus into a binary or hex value. The Tektronix
MSO Series also creates an event table, displaying the logic
states as a binary or hex value. Each state is time-stamped,
simplifying timing measurements.
The Tektronix MSO Series decodes parallel buses using
clocked or unclocked formats. For clocked decoding, the
MSO determines the logic state of the bus at either the rising
edge, falling edge or both edges of the signal you specify as
the clock. This means only the valid transitions on the bus are
shown, excluding any transitions that happen when the data
is not valid. For unclocked decoding, the MSO decodes the
bus at every sample point, showing every transition on the
bus. When the MSO uses clocked decoding, the decoded
bus display and event table are very similar to the state display
of a logic analyzer. Since bus decoding is a post acquisition
process, you have the flexibility to change the decoding format
during analysis.
The Tektronix MSO Series simultaneously decodes up to
two to sixteen buses, depending on the model. The buses are
defined as parallel or serial (I
2
C, SPI, USB, CAN, LIN, FlexRay,
RS-232/422/485/UART, Ethernet, MIL-STD-1553, and I
2
S/
LJ/RJ/TDM). The parallel bus is composed of any of the
digital channels D0 through D15. The serial bus is composed
of any of the analog channels 1 through 4 and the digital
channels D0 through D15. The MSO2000B, MDO3000, and
MDO/MSO4000B Series provides maximum design visibility
by displaying up to four analog channels, four reference
waveforms, one Math waveform, four buses and 16 digital
channels at one time. The MSO5000B Series provides even
greater analysis capabilities, with up to four Math waveforms
and 16 buses at once.
Figure 3. Decoded data is shown in an event table which is similar to a logic analyzer’s
state acquisition display.
Figure 4. Probe color coding matches waveform color coding, making it easier to see
which signals corresponds to which test point.