The W2353EP USB Compliance Test Bench helps solve the problem of simulation-measurement correlation. In the past, the pre-manufacture design could be simulated and tested using compliance tools from an EDA vendor. And the post-manufacture prototype could be bench tested using compliance tools from test and measurement instrument vendors. However, because of subtle differences between the two vendors independent approaches to compliance, it was almost impossible to correlate the two. This opened the possibility of the pre-manufacture design passing and the post-manufacture prototype failing, necessitating a time-consuming and expensive design spin. In contrast, USB Compliance Test Bench leverages the exact same industry-leading Compliance App used on Keysight Infiniium oscilloscopes. It mimics a real hardware test bench, and, using a scripting technology called “Waveform Bridge,” emits the same waveforms that the Infiniium app receives when you are testing in your lab. Thus, the exact same tests – no ifs, ands, or buts -- are applied to both the pre-manufacture simulated design and the actual post-manufacture prototype.
The product itself consists of two parts: the Simulated Test Bench, and the Waveform Bridge script.
Simulated Test Bench
The simulated test bench is composed of subcircuits, namely a USB transmitter, a channel, and a USB receiver. The circuit runs under the pre-requisite ADS Channel Simulator in bit-by-bit mode for time domain waveforms. The generic chip I/Os are represented by specially created IBIS AMI models, but you can swap out one or both of these with IBIS AMI models that are more specific to your design, such as those from an IC vendor that represent a specific IC I/O. Likewise, any or all parts of the generic channel model cascade (consisting of the transmitter package, circuit boards, connectors, receiver 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 one of more lanes on the post-layout motherboard.
Waveform Bridge script
Once the simulated testbench has been adopted to reflect your pre-manufacture design, the Channel 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.
Use with U7243B-1TP USB Compliance Test Application
The file that the Waveform Bridge writes can be read into the U7243B-1TP USB Compliance Test Application for Infiniium 9000 and 90000 Series Oscilloscopes. This application is now available with an offline/remote mode, meaning that it can run not only on live data from an oscilloscope, but now also using stored (“offline”) data. In addition, you can now run the application in “remote” mode meaning that it can run on any Windows PC (including the one you run Advanced Design System (ADS) on), not just the PC embedded in the oscilloscope. In this way you can be assured that the tests you run on the pre-manufacture design simulation will be identical to the ones you will run when the prototype is subsequently manufactured.