Outcome 2Evaluate ECAD Software Packages

Expectation after studying this outcome? Student able to evaluate ECAD software packages

and report on their performances

Student able to interpret manufacturers’ user instructions to set up correct working environment.

Student able to perform exercises to assess the performance of ECAD software packages

Student able to evaluate and report the results of exercises

What to look out for? Some major aspects of ECAD software package to

evaluate:

Suitability to the job requirement (pg 2-3)

Compatibility to your hardware (pg 2-4)

Capabilities of simulations (pg 2-6)

Ease of use (pg 2-6) & (further discussion on pg 2-14)

Project partitioning and organization, and hierarchical design capability (pg 2-7)

Suitability to the job requirement (pg 2-3) Does the software package come with enough

features to cover all the most essential operations of your job?

So, the first thing to consider is of course the category of software.

As had been briefly discussed in the previous outcome, we have 4 major groups of software: ASIC and IC design tools PLD and FPGA design tools Board-level schematic design tools PCB design tools

Suitability to the job requirement (pg 2-3) To state the most obvious, for example, Multisim

is a board-level schematic design tool, so, if you work for a firm that designs ASIC, Multisim is of no use to you.

And to state the less obvious, sometimes certain software comes packed with more than one function.

For example, board-level schematic design tools often come packed with PCB design tools as well. And while one company may be strong in producing software for the board-level schematic design tool, its PCB design tools may not be as good.

Suitability to the job requirement (pg 2-3) So, you will have to put it to the scale yourself: Does your job requirements lean towards

schematic design and simulation and troubleshooting, or more towards PCB layout?

If your job mainly involves PCB layout re-routing, a software that has the best schematic simulation features but has a difficult-to-use PCB layout tool would be but a white elephant to you.

Compatibility to your hardware (pg 2-4) Does the software run on your PC/network

platform? Can the software be incorporated seamlessly into

your PC/network? Is the minimum hardware requirement within the

budget of your project? If you run the software at its minimum hardware

requirement (if applicable), does the operation suffer any undesirable effects?

Compatibility to your hardware (pg 2-4) The next biggest disaster to buying software of the

wrong category is getting a software that does not run on your PC platform.

As a discredit to Microsoft, most of the best ECAD software were developed for UNIX.

To put it mildly, one is considered more stable that the other.

And Linux, although fast catching on in the market share, is still in the process of convincing existing big names in ECAD software developers to spend valuable resources developing ECAD software for Linux platform. So, do not mistakenly get the wrong software for your platform.

Compatibility to your hardware (pg 2-5) The obvious mistake aside, sometimes it is not

totally implausible to switch YOUR PC/network platform to suit the ECAD system that you think best suits your job requirement.

The first and foremost consideration is of course the budget and ROI (Return Of Investment) consideration.

Then in certain offices, people might want to continue using things like office tools.

To put it simply, calculate the ROI, and get some opinion polls.

Compatibility to your hardware (pg 2-5) Then there is the question of whether your

hardware could support the software. Some evaluation needs to be done to assess the

speed of simulation when the ECAD software runs on your PC/network.

Merely able to operate the ECAD is often not good enough.

Especially when your design gets big and multi-leveled and complex, you must make sure your PC/network has enough “brawn” to handle the simulations. And needless to say, stability must come alongside with speed.

Compatibility to your hardware (pg 2-5) The most cursed thing to happen is to have the

PC hanging or power failure in the middle of an important simulation.

So, you must also ensure hardware resilience and stability, and also ensure the stability of power supply.

Network backup is also very crucial to ensure that you do not lose any important files due to human error or hardware failure or virus attack.

Capabilities of simulation (pg 2-6) First off, you would like a wide range of

simulation capabilities then, beyond that, merely having the right features is not enough; those features should work with a desirable speed and performance level.

You should test the simulation capabilities of the software packages using benchmark circuits or designs to measure the performance in terms of accuracy of results and speed of processing.

Capabilities of simulation (pg 2-6) Areas to look out for includes the range of

features, the range of simulation, resolution of simulation, speed, accuracy and stability of the various simulations.

This will be further discussed with more examples in page 2-9.

Ease of use (pg 2-6) As you are evaluating and using the software

package, pause from time to time to record what you feel about the user-friendliness of the user interface.

If the software easy to control? Is the component library easy to access? Are the simulations and tests easy to setup? Are the test results easy to access and provides

you with enough information at a glance? Does any of its features make it easy for you to

create and manipulate large and complex designs?

Ease of use (pg 2-6) Ease of use is a very subjective thing, and yet, you

cannot discount its importance just because of its subjectivity.

And really, because of its subjectivity, there is no absoluteness when it comes to judging whether an ECAD software is easy to use, or, is user-friendly.

As proof of the unpredictable subjectivity of the question of ease-of-use, I know of a left-handed friend who simply refuses to change his mouse-configuration into left-handed mouse, for the reason that he was so used to using a right-handed mouse, a left-handed mouse would hinder him more than helping him.

Ease of use (pg 2-6) Hence, it is very important for the potential users

themselves to sit down with certain evaluation forms and make a record of what they like and dislike about the software, and at the end of the day, see whether the likes outweigh the dislikes.

Project partitioning and organization, and hierarchical design capability (pg 2-3) How easy are they to use? How seamlessly can different hierarchical levels

be integrated during simulated tests? If you work in team, how well does the software

network and keep track of the design changes going on over the network of designers?

Project partitioning and organization, and hierarchical design capability (pg 2-3) How good is the networking capability of the ECAD

software you are evaluating? The only way to evaluate this is to have a team sit down

around the network and rehearse out a known-working project, and have them comment on the following aspects: Is any changes by one member in the team

immediately and accurately reflected on the workspace of the other members?

How are conflicting actions resolved? How easy is it to trace the performed actions and

tasks? Does the software accurately log all actions for future

tracing?

Project partitioning and organization, and hierarchical design capability (pg 2-3)

How easy is it to view various partitions of the project, especially those of the other members in the team?

Is there an easy, integrated way to communicate effectively with member on the team?

How easy is it for the team members to access any part of the overall design hierarchy, and how is the accessibility controlled?

Is the accessibility control bogging down any one in the team?

Or, if the accessibility control is a bit loose, does it compromise design integrity or threatens to jeopardize the safe-guarding of individual work?

Conclusion (pg 2-8) Oftentimes, satisfaction is a very subjective thing. So, other than relying on factual evaluations such

as the 5 aspects discussed above, it would also help tremendously to have the users of the ECAD software rehearse known-working projects on the software and comment on the more intangible things such as whether they are comfortable with the various control interfaces, the software layout (even the colors!!), the way results were logged and reported, etc., etc.

Conclusion (pg 2-8) And then there is also the after-sale support and

possibility of customization. Big names mean nothing if they cannot stoop to

carry out customizations for lesser-scale businesses.

So, sometimes a good after-sale support and customization could cover for certain short-coming in terms of features.

Do not forget to take this into consideration as well.

Further Discussion on Simulation Capability Generally speaking, we should look at the following:

Range of simulation capabilities (pg 2-9)

Range of simulation (pg 2-11)

Resolution of simulation (pg 2-11)

Speed of simulation (pg 2-11)

Accuracy of simulation (???)

Stability of simulation (pg 2-13)

Range of simulation capabilities (pg 2-9) Some of the most common simulations performed by an

ECAD system include: DC analysis AC analysis Transient analysis Fourier analysis Noise analysis Distortion analysis Sensitivity DC sweep Parameter sweep Temperature sweep Poles and Zeros analysis Transfer function Worst case analysis Monte Carlo analysis

Range of simulation capabilities (pg 2-9) Most ECAD software also comes with simulated

instruments such as: Multimeter Oscilloscope Function generator Bode plotter Logic analyzer Logic converter Wattmeter Distortion analyzer Spectrum analyzer Word generator

Range of simulation capabilities (pg 2-9) Is more the merrier? Not always. It again boils down to what kind of work do you

do most. And sometimes, you may even need to consider

the individual performance of each analysis and instruments.

In the daily work of your position, what analysis or instrument would normally be used the most frequent?

These are the analyses or instruments you have to pay extra attention to when evaluating.

Test them rigorously.

Range of simulation (pg 2-11) This refers to the maximum range of the

frequency span, or the time span it is able to log without adverse effect towards the processing speed or the stability of the simulation.

To put it simply, if you are involved in designing circuits that operate in the RF and microwave region, this is a big concern, as not all software may simulate to that region, or may not be as fast or accurate.

Resolution of simulation (pg 2-11) For example, when doing transient analysis, what

is the maximum time resolution an ECAD software could achieve, or could perform with satisfactory speed?

You would take this into serious consideration if your works require you to pay attention to minute voltage spikes in the design or if your works are constrained by stringent requirement on the rise-time, fall-time, propagation delay, etc.

Resolution of simulation (pg 2-11) Another area of resolution is the component

values. To what accuracy can you set the component values?

Or the voltage and current reading resolutions; to what resolution is the simulation performed?

Does it fulfill your job requirement?

Speed of simulation (pg 2-11) At what ratio is the simulation time to real-time? And if any simulation is required to run in real-

time, how much does it compromise the accuracy of the simulation?

Sometimes, simple tests could tell you quite a lot.

For example, the following charts show the relationship between component counts (with various passive-to-active-component-ratio) and the simulation-time-to-real-time-ratio, of the Multisim software, run on a platform of Microsoft NT with a 500MHz processor and a RAM capacity of 128MB:

Simulation Speed

0

200

400

600

800

1000

0 10 20 30 40

Component count

Sim

ula

tio

n-t

o-R

ea

l tim

e

rati

o 1:3 to 1:4

3:4 to 3:5

Active-to-Passivecomponent ratio

You could see from the chart that when the active-to-passive component ratio is low (between 1:3 to 1:4), the increase in component count does not affect much the simulation-to-real time ratio (staying around 1 simulation second to every 200 real seconds). But when the active-to-passive component ratio is high (between 3:4 to 3:5), the amount of simulation required for the active components starts to take its toll, in effectual slowing the simulation rate at an exponential incline.

Stability of simulation (pg 2-13) And sometimes, when speed is not possible, we

would at least require stability. If we must run a simulation or test-run over-night,

we would not want the simulation to suffer any error and then aborts itself.

Further Discussion on Ease-of-Use (pg 2-14) As mentioned before, the question of whether an

ECAD software is user-friendly is a very subjective consideration.

But it is not totally impossible to evaluate whether a certain ECAD software is suitable to your work place.

Next page shows an example of the actual “grumbling” of a user when using the MultiSIM software.

All you need is to have your team of people sit down to the software and jot down all the annoyed feelings or the amazed feelings spontaneously and impromptu when using the software, and you would have a rather frank review of the software.

Assignment 2 10% of the total coursework marks. Maximum 2 persons in a group. Provide the web address of information

gathered. Marks will be deduct if the lecturer finds

out any “KES TIRU-MENIRU”. In some case, zero marks for the particular group of student.

Cut-and-paste directly from the source, marks will be deduct.