eldo_user

Introduction to Eldo
Getting Started With the Eldo Simulation Flow
During a mixed-signal, or pure analog, simulation, Questa ADMS uses Eldo to simulate the
following:
• A mixed-signal design that includes SPICE subcircuits as components.
• A SPICE netlist that includes VHDL-AMS and VHDL design entities or Verilog-AMS
and Verilog modules as components.
• A pure SPICE netlist.
See the Questa ADMS User’s Manual.
Verilog-A
Verilog-A is an analog subset of the Verilog-AMS language, for use to help design analog
systems with high-level behavioral descriptions, as well as structural descriptions of systems
and components. The default Verilog-A implementation in Eldo is the same as that used by
Verilog-AMS in Questa ADMS. Eldo and Questa ADMS can share the same compiled Verilog-
A modules.
See the Eldo Verilog-A User’s Manual.
Waveform Analysis
The EZwave graphical post-processor enables waveform analysis and post-processing of
simulation results. The native waveform format of EZwave, called “wdb,” is extremely efficient
for manipulating huge databases. EZwave can load gigabytes of data in seconds. EZwave can
also load most popular waveform formats, and operates on both analog and digital signals.
See the EZwave Users Manual.
Viewing ASCII Simulation Output Files
You can use the AMS Results Browser to view simulation results and associated files.
Depending on the file format, results may be sorted, filtered, grouped, searched, printed, copied,
and exported.
The AMS Results Browser is mainly intended to be used to view Eldo outputs, but you can also
use it to view SPICE input files and any text file.
See the AMS Results Browser.
Getting Started With the Eldo Simulation Flow
The basic Eldo simulation flow is to setup a .cir netlist file, run the Eldo simulation on the
netlist file, then analyze the generated results.
This example consists of a simple cascade of three inverters. Figure 1-1 and Figure 1-2 show
the circuit diagram for the cascade together with the inverter subcircuit. To create the Eldo
netlist, node names must be assigned to the circuit. The complete netlist is provided.
Eldo® User's Manual, 15.3 31