IBIS is sometimes known as the bird of knowledge, but is also the popular standard in modeling I/O buffers. Well, IBIS recently grew some big new wings when the 5.0 version of the spec was ratified. Those big wings include support for algorithmic modeling of SerDes transceivers. Instead of just modeling with numbers and tables, the 5.0 standard now allows software modules or dynamically linked libraries (DLLs) to be included in the model. This well defined software interface allows for very sophisticated algorithms that match the sophisticated equalization algorithms that take place inside the SerDes to be implemented by signal integrity simulation tools.Official support for IBIS 5.0 AMI models is now available in Allegro PCB SI. While Cadence has supported the AMI standard for over two years, it was not until recently that the IBIS committee released their official parser and that has now been integrated into the latest PCB SI release.
Users of PCB SI should navigate to downloads.cadence.com, select SPB163 and download the latest hotfix.Cadence is pleased that the work they first validated with IBM at DesignCon 2007 (see Interrogating the chips in 2007 EE Times article) has reached this ultimate level of standardization. It took a lot of time, energy, and cooperation with other companies, but both Cadence and Cadence customers will be well served for their patience and persistence.After you have a chance to download the latest hotfix and work with our sample AMI models, please let us know your feelings about the “out-of-the-box” IBIS-AMI support in Cadence Allegro PCB SI.Brad Griffin
Does IBIS support include IBIS to DML translation from IBIS 5.0 or even 4.1 format to DML including all IBIS keywords? Currently ibis2signoise only translates keywords found in IBIS 3.2 which is about 10 years old. Thanks.
Specifically related to the IBIS 5.0 keywords, with today's build (2/12/10) we support all the keyword constructs new to the 5.0 release (specifically the AMI model calls). This is included in the HotFix/ ISR and updates the Ibis2signoise.
Let me also add that we are using the parser provided by the IBIS committee, so all supported keywords are read. There may be a handful of those keywords that are optional where we parse them and don't perform any action (i.e. Keyword: [Test Data] aka Golden Waveform). If you are having trouble with any particular keyword, please contact Cadence Support and we will look at it right away.
Thank you all for the replies. How can I influence Cadence to update the ibis2signoise translator to include translation of all keywords found in the current IBIS standard? As an example, the DML equivalent to sub parameters such as Vmeas found under the keyword Model Spec would be very helpful. The addition of AMI model calls is definitely a step in the right direction and I applaud Cadence for this valuable addition to Allegro PCB SI.
The Vmeas sub parameter under the keyword Model Spec is a key component to our DDR2 / DDR3 bus analysis feature. If there is a particular problem you are having with this or any IBIS keyword, our Cadence Support team will be happy to address the issue.
I hope you will try the latest version of PCB SI and let us know your feedback.
I downloaded the Xilinx Virtex-6 rocketIO IBIS-AMI model. In SigXplore PCB SI GXL v16.3, I set the search path of SI Model Browser accordingly, but it does not recognise this xilinx ibis-ami model!!!
Hi Weiming Qian,
Xilinx has some AMI kits for Allegro PCB SI that they are in the process of qualifying. If you contact Xilinx, they may be willing to get you an advanced version of the kit if you ask.
I tried to use ibis2signoise tool to convert Xilinx virtex-6 IBIS-AMI model into dml library, but the ibis2signoise just died half way through with a popup window saying "ibis2signoise.exe has stopped working"!!!
Could someone please tell me what is wrong here?
ibis2signoise -nu in=xilinx_v6_gtx.ibs out=xilinx_v6_gtx.dml
It might be best to contact our Customer Support team so that they can assist you with this specific issue.
With reference to the Xilinx AMI kits for Allegro PCB SI mentioned a few months back. Does anyone know if those are available yet?