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Design >> RF Design >> PSS simulation error-Insufficient memory available
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Message started by rramp on Oct 13^th, 2004, 10:30pm

Title: PSS simulation error-Insufficient memory available
Post by rramp on Oct 13^th, 2004, 10:30pm

Hi freinds !!! :)

I got some troubles during pss simulation - receiver top simulation.
The following error reported after spectreRF simulaiton
"Internal error found in spectre during check, during IC analysis, .... ..... Insufficient memory available"
So I wondered that my system has not sufficient memory and checked memory size. It has 7GB physical memory and 20GB swap memory.
Could you please give me advice for resolving this problem?

Title: Re: PSS simulation error-Insufficient memory avail
Post by Andrew Beckett on Oct 14^th, 2004, 10:07am

Just because you have 7GB memory does not necessarily mean that an application can use it. Spectre is a 32 bit executable (64 bit version is currently in engineering release), and so can access up to 2Gbyte (2^31) on HP or Linux, and 3.7Gbyte on Solaris.

If it is failing during the initial condition, it may be because the circuit is quite large, or that spectre's front end is using a lot of memory because the model files are complex and veyr parameterised.

If so, you should try using IC5141, and use the +csfe command line option to spectre, or if running under ADE, try using:

envSetVal("spectre.envOpts" "useCsfe" 'boolean t)

before starting DFII (type this in the CIW).

The memory usage of the new front end is significantly lower, and this may buy you enough to run the simulation.

What is the circuit inventory that the simulator reports?

Regards,

Andrew.

Title: Re: PSS simulation error-Insufficient memory avail
Post by Razer on Nov 3^rd, 2004, 10:03pm

Hi,
I get the same Insufficient memory error :( . I use IC5033.500, I run the PSS simulation on a PLL from Ocean script on sparc-solaris system with over 4G ram & plenty of swap. Here is the inventory :
nodes 937
equations 955
iprobe 1
bjt 5
bsim3v3 2157
capacitor 2
quantity 6
resistor 4
vsource 7
Thanks
Razer

Title: Re: PSS simulation error-Insufficient memory avail
Post by Andrew Beckett on Nov 4^th, 2004, 10:40pm

Can you post the excerpt of the log file (the surrounging
10 lines say) showing the error?

Also, what is the relationship between the PSS fundamental frequency and highest frequency in your circuit? Are you using the "swapfile" parameter for PSS.

At the moment I don't have much information to go on.

The circuit is large, but not immense.

What technology are you using? That might give me a clue as to whether it is likely to be front-end related.

Regards,

Andrew.

Title: Re: PSS simulation error-Insufficient memory avail
Post by Razer on Nov 7^th, 2004, 5:33pm

Thanks,
Here is the excerpt :

pss: time = 70.31 us (61.5 %), step = 11.87 ps (2.37 m%)
pss: time = 70.32 us (62.3 %), step = 66.41 ps (13.3 m%)
pss: time = 70.32 us (62.5 %), step = 19.4 ps (3.88 m%)
pss: time = 70.32 us (62.6 %), step = 3.153 ps (631 u%)
pss: time = 70.32 us (62.7 %), step = 3.065 ps (613 u%)
pss: time = 70.32 us (62.8 %), step = 16.87 ps (3.37 m%)
pss: time = 70.32 us (63.6 %), step = 39.5 ps (7.9 m%)

Fatal error found by spectre at time = 70.3236 us during periodic steady state
analysis `pss'.
Insufficient memory available.

Conv norm = 813e+03, max dV(I0.I23.net34) = 2.5 V, took 1.96749 ks.

Fatal error found by spectre at time = 70.3236 us during periodic steady state
analysis `pss'.
Insufficient memory available.

Analysis `pss' terminated prematurely due to error.

The highest frequency in the circuit is 40 times the PSS fundamental frequency.

The process is a 0.13u, 1.5V CMOS process.

Thanks
Razer

Title: Re: PSS simulation error-Insufficient memory avail
Post by Razer on Nov 7^th, 2004, 5:35pm

forgot to add this:
Iam not using the "swapfile" parameter in PSS

Title: Re: PSS simulation error-Insufficient memory avail
Post by Andrew Beckett on Nov 8^th, 2004, 11:53pm

Given what you say, I would try using swapfile. Make sure that you set it to a file on a disk on the local machine (you don't want swap data having to go around the network), and if on a Sun (and you have tmpfs enabled) don't put it in /tmp (because it is swapping twice if you do that).

swapfile can allow you to access more than the available memory for a 32 bit program, because it does the memory management itself.

You may also benefit from using the new front end (as I described in my previous post) in IC5141; your mileage may vary as it depends on the model files as to how much an improvement this makes. With some model files I've seen circuits go from running out of memory to only using 200Mbytes... but that's not always going to be the case.

Best Regards,

Andrew.

Title: Re: PSS simulation error-Insufficient memory avail
Post by Rae YE on Nov 16^th, 2004, 12:41am

Hi,
I have ever met such problems when I simulated my circuit by using pss simulation. Then I turned to Periodic distortion analysis, then it worked.

I am not sure whether it works in your case.

Title: Re: PSS simulation error-Insufficient memory avail
Post by Razer on Nov 21^st, 2004, 9:54pm

Andrew Beckett,
The memory problem is solved after specifiying the swapfile. But still the PSS simulation does not converge, I have to deal with it myself.

thanks
Razer