Comparision Spectre HSpice HSim

[jk]

hsim turbo mode

I would appreciate comparative information on simulation "quality" (convergence, etc) of the above mentioned simulators for analog circuits with some 100 to 1000 transistors. are there convergence or other known trade offs with hsim (which i assume as the fastest simulator) ? which simulator would be the best when invoking it several 1000 times on a design with slightly modified parameters each time (perhaps parallel invokation of several simulators on different machinesis would be also possible) are there other interesting alternatives (when simulation speed is essential ?)

best regards

 

[okguy]

Search each simulator on this forum to idea.
Here is also a presentation.

OkGuy.

 

[elone]

For 100 to 1000 transistors , hsim not suit!

 

[edaguy69]

It's not an easy job to compare different tool. it depends on the nature of your design( big or small, analog or digital), interfacing with other tools you had or you will buy, the foundry you are using ( can the foundry supply to you the model working with you tool), the expertise of your engineer, the learning curve and the budgetyou plan dor the tool. It's a one million dollars question. It can take the whole book to analyze. Here is some of my humble opinion:
Hspice, Smart Spice, Spectre. Accusim are in one group
StarsimXT, Hsim, TimeMill, Nanosim are in one group.
Particularly here are the strong point of Hspice and Spectre:
Strong point of Hspice:
-support more model than other.
-Accuracy
Strong point of Spectre:
-Integrated well with other Cadence tool (Cadence have a very good and popular schematic capture)
-Support a more liberal syntax
-Have a lot of RF feature that Hspice doesn't have

It's not a clear cut question like a van, a truck, a SUV, a sedan, a sport car which one is better.

 

[edaguy69]

HSIM only took less than 3 minutes to simulate my entire full custom 32 x 32 register file. It really save me a lot of time when I tried to debug my layout. When my simulation fails, I can quickly modified my layout & resimulate it. However, this is impossible for me to do so under HSPICE or SmartSpice for such a large circuits. Both HSPICE & Smartspice just take too long ....

I aggree with you. But when you should be used. Hsim, StarSim or nanosim will run the fullchip simulation in a fraction of time with the price of accuracy sacrify. The right tool for the right job!

 

[elone]

Yes ! You can't use hsim for high accuracy analog circuit !

 

[dinosaur]

Hsim is a good tool for mixed-signal simulation (large part in digital and
small part in analog)

Dino

 

[CatKing]

For all pure logic circuits, you can use any fast spice simulator as nanosim/star-sim/hsim/ultrasim/mach/adit, all of them are based on the same technology - I/V LUT. They use spice model to get the look-up-table of I/V charactor of the models, then use these LUT during the simulation process, it's fast but not accurate.
If you want hi-accurate simulation such as PLL, OSC, HSPICE/Spectre/Eldo still are the best solution.

 

[Amuro]

In device level, I still believe that SPICE-liked programs are the best i.e. HSPICE/Spectre etc. On the other hand, in system level, Hsim/StarSim etc. should be better (in term of time and cost).

 

[kwkam]

I usually use HSpice for small block of analog circuit simulation. Then use HSIM for the whole circuit simulation.

 

[superluminal]

As edaguy69 said ; there is 2 main categories of SPICE simulators:

1) " Classic " simulators (HSPICE, ELDO, SPECTRE...etc) : they are strong simulators that use many advanced & sophisticated numerical techniques to get you the level of accuracy you want. Actually many of them are old & had not changed from long time ago ( I know that actally one of them had had no kernel updates from late 80's !)

2) Fast SPICE simulators (StarsimXT, Hsim, TimeMill, Nanosim ...etc) : they are fast & use less efficient numerical analysis method & use techniques ( like hierarchy simulation ) to give you the speed you want.

In few words ; going deep in circuit analysis ( say, to test your topology ) => use the classic SPICE simulators.

To review the whole system response ( say, to check how o/p of part A affects part B ) => use fast SPICE.

 

[jako123]

HSpice is quite fast - indeed - but not so comfortable!!!

there is no advantage with a disadvantage!


ciao

 

[RC13]

for a ams design,
1. at sub-block level (small block), use hspice to simulate, and try to estimate the higher level results, you should meet all the spec. at this level,
2. at fully system level, for functionality check, use hsim to verified.

you can actually forget about using spectre for ams, but you can use it for rf-ams design.

 

[adanshen]

hsim and spectre both get accuracy problem, hsim take subcells as the same,
so it can speed up the simulation

 

[obrian]

I used ADiT and it does not have accuracy problem like HSIM.
With ADiT, I can go to many different modes.
Spice mode if I need accuracy.
Turbo mode if I want speed.
Subcircuit mode if I want full chip verfication with accuracy.
VPI/HDL mode if I want to do SoC simulation with a lot of A/D and D/A.


And sometimes I use ADiT-Turbo with Hspice's technology files too. =)

 

[okguy]

Never heard about it!
Is there any University benchmark to compare it with Hsim, Nanosim, Starsim, ... in term of accuracy and speed for reference design such as PLL, AD/DAC or memory ?

 

[Btrend]

starsim is not so good as adit.
I had tried to verify my full chip simulation using starsim & adit,
my chip is 20% digital + 80% analog,
When using starsim, I should tried for many times what option make
its output "reasonable", there is always "un-resonalble" behavior using
starsim which make me spend a lot of waste time in debuging the "option".
But with adit, I can get the fast speed and still got the "resonable" result
with few options if needed.

 

[take_care00]

Hi,

Did anyone compared/used the latest HSIM version which is called by NASSDA as HSIM Plus?

According to Nassda the upgrade is provided free of charge for customers with maintenance agreement. The benchmark published in their website (**broken link removed**) is very impressive.

Did someone compared HSIM plus to Adit and the latest version of Nanosim (Nanosim got many improvments in 2003)?

Take care.

 

[obrian]

I thought HSIM plus was just repackaged HSIM with "options"
I heard one of the options were SPICE netlist parser.. How are you going to run simulation if you don't purchase that option! hehe..
Probably my misunderstanding.. but I thought it was funny.

I heard HSPICE improved its speed by 25% but has anyone verificed this?
Nanosim (with starsim combined) should has a lot of improvements.
But among HSIM, Nanosim and ADiT, I think ADiT is the easiest to use.
I thought using ADiT was quite similar to using HSPICE.. (Which I used a lot during college years!)

Hi,

Did anyone compared/used the latest HSIM version which is called by NASSDA as HSIM Plus?

According to Nassda the upgrade is provided free of charge for customers with maintenance agreement. The benchmark published in their website (**broken link removed**) is very impressive.

Did someone compared HSIM plus to Adit and the latest version of Nanosim (Nanosim got many improvments in 2003)?

Take care.

 

[tlihu]

I thought HSIM plus was just repackaged HSIM with "options"
I heard one of the options were SPICE netlist parser.. How are you going to run simulation if you don't purchase that option! hehe..
Probably my misunderstanding.. but I thought it was funny.

I heard HSPICE improved its speed by 25% but has anyone verificed this?
Nanosim (with starsim combined) should has a lot of improvements.
But among HSIM, Nanosim and ADiT, I think ADiT is the easiest to use.
I thought using ADiT was quite similar to using HSPICE.. (Which I used a lot during college years!)

Hi,

Did anyone compared/used the latest HSIM version which is called by NASSDA as HSIM Plus?

According to Nassda the upgrade is provided free of charge for customers with maintenance agreement. The benchmark published in their website (**broken link removed**) is very impressive.

Did someone compared HSIM plus to Adit and the latest version of Nanosim (Nanosim got many improvments in 2003)?

Take care.

HSPICE 2004.03-SP1 runs faster than pervious version, I can feel that. However, I think "25% faster" is just another commercial terminology.