[ibis-serdes-backchan] Simple description of AMI Parameters

From: "Walter Katz" <wkatz@xxxxxxxxxx>
To: <ibis-serdes-backchan@xxxxxxxxxxxxx>
Date: Thu, 10 Feb 2011 14:05:17 -0500
All,

 

AMI models consist of executable DLLs and a .ami file. The .ami file is an
ASCII file that defines parameters in a parameter tree format. Each
parameter has a Name, Type (String, Integer, Float, Tap, Boolean), a Usage
(In, Out, InOut, Info), a Description, and a set of Allowed Values. 

 

Usage

In

 "In" parameter Values are passed into the DLL The EDA tool is responsible
for selecting a Value for each In parameter based on its allowed values. An
example of an In parameter might be the value of a Tx pre-cursor tap.

Out

"Out" parameter Values are determined by the DLL and passed back to the EDA
tool. An example of an Out parameter might be the value of a DFE tap
determined by the DLL.

InOut

"InOut" parameter Values are passed into the DLL, modified by the DLL and
passed back to the EDA tool. An example of an InOut might be the value of a
DFE tap that can be initialized by the EDA tool to a specific value, but
modified by the DLL as a result of it determining an improved value. In this
case the EDA tool may help the Rx model reach optimized DFE taps quicker by
getting a improved starting value for it.

Info

"Info" parameters are not passed into the DLL, but are used to give
information to the EDA tool on how to use the DLL, or how to process the
data returned by the DLL. An exemple of an Info parameter is Tx_DCD. This
would tell the EDA tool how much duty cycle distortion to apply to the
stimulus pattern input to the DLL in time domain simulation.

 

Description

EDA tools normally control the usage of an AMI model with a GUI that allows
the user to configure parameters that control the operation of a buffer. The
"Description" is a text string that the EDA tool can use as a tool tip in
this GUI.

 

Allowed Values

The .ami file has a flexible method that the model make can communicate to
the EDA Tool and User of the model the allowed values that can be assigned
to a parameter. The following methods of specifying "Allowed Values" are:

Value

            A single value.

List

            An list of allowed values

Range

            A range of allowed values

Increment

            A range of allowed values constrained to values separated by a
fixed amount

Steps

            A range of allowed values constrained to values separated into N
equally spaced steps

Corner

Three values representing typical, slow and fast corners of the buffer

 

 

Parameters are divided into two classes; Reserved Parameters and Model
Specific Parameters. Reserved Parameters are defined in the IBIS
specification. Model Specific Parameters are used to define the operation
specific to a model.

 

The task of this reflector is to create a new set of generic Reserved
Parameters to control the statistical and time domain communications between
Tx and Rx models and the EDA tool, and to define Reserved Parameters for
specific Backchannel Protocols such as PCIe-Gen3, IEEE Ethernet 25G, .

 

Walter 

 

 

 

Walter Katz

Chief Scientist

Signal Integrity Software, Inc.

wkatz@xxxxxxxxxx

303.449-2308
[ibis-serdes-backchan] Simple description of AMI Parameters

Other related posts:
