W2351EP Datasheet, PDF (2/4 Pages) Keysight Technologies – DDR4 Compliance Test Bench

02 | Keysight | W2351EP DDR4 Compliance Test Bench - Data Sheet
Benefits Across The Development Process
Run a sign-off compliance test on the simulated test bench waveforms before commit-
ting to fabrication. Run the exact same tests on the simulated testbench that will be run
on the oscilloscope in the test lab when prototypes come back from fab.
–– DDR controller designer at an IC company may swap out the simulated testbench’s
generic controller model with actual controller I/O model
–– PCB/package/DIMM designer at an OEM or IC company may swap out parts of the
simulated testbench’s generic channel cascade with the post-layout EM-based
model of actual package (or PCB or DIMM)
–– DRAM I/O designer at an IC company may swap out the simulated testbench’s ge-
neric DRAM model with actual DRAM I/O model
Figure 1. Engineers can apply the same set of compliance tests and receive the exact same compli-
ance report on the simulated design as they will use on the fabricated prototype.
Simulated Test Bench
The simulated test bench is composed of subcircuits, namely a DDR controller, a
channel, and a DDR memory chip. The circuit runs under the pre-requisite ADS Transient
Simulator. The generic chip I/Os are represented by traditional IBIS models, but you can
swap out one or both of these with either IBIS or netlist models that are more specific to
your design. Likewise, any or all parts of the generic channel model cascade (consisting
of the controller package, motherboard, DIMM connector, DIMM PCB, memory package)
can be replaced with pre- or post-layout models. For example, an electromagnetic (EM)
field solver can be used to create an S-parameter model of a byte lane on the post-
layout motherboard.
Waveform Bridge Script
Once the simulated testbench has been adopted to reflect your pre-manufacture design,
the Transient simulation runs writing the appropriate waveforms to the dataset. The
Waveform Bridge script is a post-processing step that takes waveforms in the data set
and writes them to a file that the Infiniium Compliance Test Application can parse.