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Simulators >> Circuit Simulators >> Spectre Monte Carlo Simulation export error
https://designers-guide.org/forum/YaBB.pl?num=1462201430

Message started by Noah1988 on May 2^nd, 2016, 8:03am

Title: Spectre Monte Carlo Simulation export error
Post by Noah1988 on May 2^nd, 2016, 8:03am

Hi all,

Hi

I get this error message when I run Monte Carlo simulation (in SPECTRE) for a resistive memory bit cell:

Warning from spectre during transient analysis `mtj_mc_tran1', during Monte Carlo analysis `mtj_mc'.
WARNING (SPECTRE-16002): Monte Carlo iteration 5 terminated prematurely because of the following error(s):

Error found by spectre during transient analysis `mtj_mc_tran1', during Monte Carlo analysis `mtj_mc'.
ERROR (SPECTRE-8003): mtj_mc_tran1: Error evaluating ocean expression `v_node1=v("node1")'.

Here, is the code as such:

Code:

// cell and access transistor

Xmtj (node1 node2) stt_mram_singleMgo Rp=R_p Rap=R_ap //cell

xm0 (BL WL node1 0) nchsvt_mac l=28n nf=2 nfin=1 tfin=7n //Finfet

// Wire Parasitics

rsub (sub 0) resistor r=0.0000001
csub (sub 0) capacitor c=0.1fF

rbl (BL 0) resistor r=0.0001
cbl (BL 0) capacitor c=1fF

rwl (WL 0) resistor r=0.0001
cwl (WL 0) capacitor c=1fF

rmtj_SL (node2 SL) resistor r=0.0001
cmtj_SL (node2 SL) capacitor c=1fF
//ends MRAM_CELL
//////////////////////////////////////////////////////////////////////////

// Sources

Vbl_1 (BL 0) vsource type=pwl wave=[0 1 10n -1 20n 1 30n -1 40n 1 50n -1 60n 1 70n -1]

Vwl_1 (WL 0) vsource type=pwl wave=[0 0 10n 1.2 20n 1.2 30n 1.2 40n 1.2 50n 1.2 60n 0 70n 0]

// monte carlo analysis

mtj_mc montecarlo variations=process numruns=5 saveprocessparams=yes processscalarfile="./mtj_montecarlo.dat"
{
dcop1 dc // a "child" analysis
tran1 tran start=0 stop=70n// another "child" analysis
//export //calculations are sent to the scalardata file
export v_node1=oceanEval("v(\"node1\")")
}

I'm pretty sure it' because I'm bad at circuit design rules and there is a silly error somewhere.

Thanks in advance.

:)

Title: Re: Spectre Monte Carlo Simulation export error
Post by Noah1988 on May 3^rd, 2016, 5:53am

IT seems like the problem is with evaluation of the transient analysis.
If I avoid the transient analysis (with only a dc child analysis), then it seems to run fine.

Hmm..
I now need to figure out a way to run a transient analysis and export the parameters of interest to plot the required histograms.