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Transient noise analysis - Simulation very slow

Hi all,

I would like to run a transient noise analysis in a mixed signal system. For better estimation of the noise bandwidth of interest I ran an AC noise analysis of my system in steady state. I found out that the relevant noise contributions occur below 10 GHz. However, when I'm running transient simulation with noise enabled up to 10 GHz and simulated time over 100 us, the simulation practically takes forever.

Without having any deep knowledge about the transient noise simulation, I came up with the idea to enable transient noise only up to 1 GHz instead of 10 GHz and compensate for the "loss of noise" by scaling it up using the noise scale parameter. I calculate the necessary scaling factor by dividing the integrated AC noise at 10 GHz bandwidth by the integrated AC noise at 1 Ghz bandwidth.

My question is very simple: Is the described methodology to speed up the simulation giving realistic results? Or am I running into trouble here without seeing an important problem?

My idea behind is that, in general, the bandwidth where the noise is generated is of course lower than the expectable 10 GHz, but within this lower bandwidth, I'm scaling up the noise artificially, such that the integrated noise over the full bandwidth ends up to be the sameas if I had simulated it up to 10 GHz.

Thank you very much in advance for your replies!

ShawnLogan over 5 years ago

Dear Tobius,

Unfortunately, the methodology you are proposing, if I understand it correctly, does not properly capture the impact of noise folding in your large signal transient noise simulation.

Basically, the nature of most large signal transient simulations is rather non-linear where intermodulation products are produced. As such, the noise will also be modulated. Hence, a linear noise factor applied to a "lower noise bandwidth" noise source than your circuit will support will not fully capture the impact of a wider noise source bandwidth passed through the same system.

However, your basic issue, as I understand it, is a slow transient noise simulation time. What are your transient noise settings and other simulation details? Can you provide the spectre.out file and/or input.scs file?

Shawn
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Tobias Schirmer over 5 years ago in reply to ShawnLogan

Hi Shawn,

thank you so much for the detailed answer. I understand your concern.

I have attached the input.scs without netlist information and spectre.out file.

Appreciate your help!

Tobias

Fullscreen 4721.input.scs.txt Download

simulator( 'spectre )
design(	 "/home/paelke/simulation/tb_lsb_segment_calibration/spectre/schematic/netlist/netlist")
resultsDir( "/home/paelke/simulation/tb_lsb_segment_calibration/spectre/schematic" )
modelFile( 
    '("$ICPRO_DIR/resources/22FDSOI/Models/Spectre/models/design_wrapper.lib.scs" "tt_pre")
)
analysis('dc ?saveOppoint t  )
analysis('tran ?stop "1u"  ?errpreset "conservative"  ?tranNoise "Transient Noise"  
		?trannoisemethod "default"  ?noisefmax "10G"  ?noisefmin "10k"  ?noiseseed "47"  
		?noisescale "1"  ?noisetmin ""  ?noiseupdate ""  ?noiseonoff ""  
		?noiseinst ""  )
desVar(	  "Vout_Iref" 450m	)
desVar(	  "Vds" 800m	)
desVar(	  "Vbias_cas_int" 600m	)
desVar(	  "Cb_storage" 1p	)
desVar(	  "Vb_lsb" 408m	)
desVar(	  "CAL_EN" 1	)
desVar(	  "Cm" 10f	)
desVar(	  "Ierror" 0	)
desVar(	  "wireopt" 11	)
desVar(	  "Ibias" 80u	)
desVar(	  "Imsb" 20u	)
desVar(	  "Tcal_lsb" 20u	)
desVar(	  "Vb_off" 0	)
desVar(	  "Vout" 800m	)
envOption(
	'analysisOrder  list("dc" "noise" "tran") 
)
option(	'dc_pivot_check  "yes" 
	'pivotdc  "yes" 
	'temp  "100.0" 
)
option( ?categ 'turboOpts
	'disableVddOverride  nil 
	'numThreads  "16" 
	'mtOption  "Manual" 
	'apsplus  t 
	'uniMode  "APS" 
)
saveOption( ?simOutputFormat "psfxl" )
saveOption( 'currents "selected" )
saveOption( 'nestlvl "2" )
saveOption( 'save "lvlpub" )
save( 'v "/BBCAL_CS6/source1_int_node_0V45" "/BBCAL_CS5/source1_int_node_0V45" "/BBCAL_CS4/source1_int_node_0V45" "/BBCAL_CS3/source1_int_node_0V45" "/BBCAL_CS2/source1_int_node_0V45" "/BBCAL_CS1/source1_int_node_0V45" "/BBCAL_CS0/source1_int_node_0V45" "/BBCAL_CS6/source2_int_node_0V45" "/BBCAL_CS5/source2_int_node_0V45" "/BBCAL_CS4/source2_int_node_0V45" "/BBCAL_CS3/source2_int_node_0V45" "/BBCAL_CS2/source2_int_node_0V45" "/BBCAL_CS1/source2_int_node_0V45" "/BBCAL_CS0/source2_int_node_0V45" )
save( 'i "/DCSW6_PROBE_IOUTP/MINUS" "/DCSW4_PROBE_IOUTP/MINUS" "/DCSW5_PROBE_IOUTP/MINUS" "/DCSW3_PROBE_IOUTP/MINUS" "/DCSW2_PROBE_IOUTP/MINUS" "/DCSW1_PROBE_IOUTP/MINUS" "/DCSW0_PROBE_IOUTP/MINUS" "/LSBREF/R0/in" "/IOUT_PROBE_CS6/PLUS" "/IOUT_PROBE_CS5/PLUS" "/IOUT_PROBE_CS4/PLUS" "/IOUT_PROBE_CS3/PLUS" "/IOUT_PROBE_CS2/PLUS" "/IOUT_PROBE_CS1/PLUS" "/IOUT_PROBE_CS0/PLUS" )
temp( 100.0 ) 
run()
DC\:CS2_V_source2_int_node = VDC("/BBCAL_CS2/source2_int_node_0V45")
plot( DC\:CS2_V_source2_int_node ?expr '( "DC:CS2_V_source2_int_node" ) )
I_total = average(clip(IT("/LSBREF/R0/in") 9.5e-05 0.000195))
plot( I_total ?expr '( "I_total" ) )
snapshot\:DCSW0_Ierr_total = (average(clip(IT("/DCSW0_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 128))
plot( snapshot\:DCSW0_Ierr_total ?expr '( "snapshot:DCSW0_Ierr_total" ) )
snapshot\:CS3_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS3/PLUS") - (I_total / 16)) 9.6e-05 9.9e-05))
plot( snapshot\:CS3_Ierr_postcal ?expr '( "snapshot:CS3_Ierr_postcal" ) )
snapshot\:CS2_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS2/PLUS") - (I_total / 32)) 1.1e-05 1.4e-05))
plot( snapshot\:CS2_Ierr_precal ?expr '( "snapshot:CS2_Ierr_precal" ) )
v\ \/LSB_CAL_CLK\;\ tran\ \(V\) = vtime('tran "/LSB_CAL_CLK")
plot( v\ \/LSB_CAL_CLK\;\ tran\ \(V\) ?expr '( "v /LSB_CAL_CLK; tran (V)" ) )
snapshot\:CS0_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS0/PLUS") - (I_total / 128)) 9.6e-05 9.9e-05))
plot( snapshot\:CS0_Ierr_postcal ?expr '( "snapshot:CS0_Ierr_postcal" ) )
DC\:CS1_V_source1_int_node = VDC("/BBCAL_CS1/source1_int_node_0V45")
plot( DC\:CS1_V_source1_int_node ?expr '( "DC:CS1_V_source1_int_node" ) )
tran\:Ierr_CS5 = (IT("/IOUT_PROBE_CS5/PLUS") - 1e-05)
plot( tran\:Ierr_CS5 ?expr '( "tran:Ierr_CS5" ) )
tran\:Ierr_CS0 = (IT("/IOUT_PROBE_CS0/PLUS") - 3.125e-07)
plot( tran\:Ierr_CS0 ?expr '( "tran:Ierr_CS0" ) )
DC\:CS4_V_source2_int_node = VDC("/BBCAL_CS4/source2_int_node_0V45")
plot( DC\:CS4_V_source2_int_node ?expr '( "DC:CS4_V_source2_int_node" ) )
v\ \/BBCAL_CS3\/CS3_CON_S1_L\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/CS3_CON_S1_L")
plot( v\ \/BBCAL_CS3\/CS3_CON_S1_L\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/CS3_CON_S1_L; tran (V)" ) )
snapshot\:DCSW1_Ierr_total = (average(clip(IT("/DCSW1_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 64))
plot( snapshot\:DCSW1_Ierr_total ?expr '( "snapshot:DCSW1_Ierr_total" ) )
snapshot\:CS0_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS0/PLUS") - (I_total / 128)) 1.1e-05 1.4e-05))
plot( snapshot\:CS0_Ierr_precal ?expr '( "snapshot:CS0_Ierr_precal" ) )
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#1 = 0
plot( \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#1 ?expr '( "#############################1" ) )
i\ \/IOUT_PROBE_CS1\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS1/PLUS")
plot( i\ \/IOUT_PROBE_CS1\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS1/PLUS; tran (I)" ) )
v\ \/BBCAL_CS3\/CS3_CAL_S1_L\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/CS3_CAL_S1_L")
plot( v\ \/BBCAL_CS3\/CS3_CAL_S1_L\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/CS3_CAL_S1_L; tran (V)" ) )
i\ \/IOUT_PROBE_CS3\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS3/PLUS")
plot( i\ \/IOUT_PROBE_CS3\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS3/PLUS; tran (I)" ) )
i\ \/V6\/PLUS\;\ dc\ \(I\) = i("/V6/PLUS" ?result "dc")
plot( i\ \/V6\/PLUS\;\ dc\ \(I\) ?expr '( "i /V6/PLUS; dc (I)" ) )
i\ \/IOUT_PROBE_CS5\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS5/PLUS")
plot( i\ \/IOUT_PROBE_CS5\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS5/PLUS; tran (I)" ) )
snapshot\:CS4_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS4/PLUS") - (I_total / 8)) 9.6e-05 9.9e-05))
plot( snapshot\:CS4_Ierr_postcal ?expr '( "snapshot:CS4_Ierr_postcal" ) )
snapshot\:DCSW4_Ierr_total = (average(clip(IT("/DCSW4_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 8))
plot( snapshot\:DCSW4_Ierr_total ?expr '( "snapshot:DCSW4_Ierr_total" ) )
DC\:CS3_V_source2_int_node = VDC("/BBCAL_CS3/source2_int_node_0V45")
plot( DC\:CS3_V_source2_int_node ?expr '( "DC:CS3_V_source2_int_node" ) )
DC\:CS3_V_source1_int_node = VDC("/BBCAL_CS3/source1_int_node_0V45")
plot( DC\:CS3_V_source1_int_node ?expr '( "DC:CS3_V_source1_int_node" ) )
i\ \/IOUT_PROBE_CS4\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS4/PLUS")
plot( i\ \/IOUT_PROBE_CS4\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS4/PLUS; tran (I)" ) )
DC\:CS6_V_source2_int_node = VDC("/BBCAL_CS6/source2_int_node_0V45")
plot( DC\:CS6_V_source2_int_node ?expr '( "DC:CS6_V_source2_int_node" ) )
output\ noise\;\ V\ \/\ sqrt\(Hz\) = getData("out" ?result "noise")
plot( output\ noise\;\ V\ \/\ sqrt\(Hz\) ?expr '( "output noise; V / sqrt(Hz)" ) )
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#2 = 0
plot( \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#2 ?expr '( "#############################2" ) )
v\ \/LSB_RESET_L\;\ tran\ \(V\) = vtime('tran "/LSB_RESET_L")
plot( v\ \/LSB_RESET_L\;\ tran\ \(V\) ?expr '( "v /LSB_RESET_L; tran (V)" ) )
snapshot\:CS6_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS6/PLUS") - (I_total / 2)) 9.6e-05 9.9e-05))
plot( snapshot\:CS6_Ierr_postcal ?expr '( "snapshot:CS6_Ierr_postcal" ) )
tran\:Ierr_CS4 = (IT("/IOUT_PROBE_CS4/PLUS") - 5e-06)
plot( tran\:Ierr_CS4 ?expr '( "tran:Ierr_CS4" ) )
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#4 = 0
plot( \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#4 ?expr '( "#############################4" ) )
DC\:CS2_V_source1_int_node = VDC("/BBCAL_CS2/source1_int_node_0V45")
plot( DC\:CS2_V_source1_int_node ?expr '( "DC:CS2_V_source1_int_node" ) )
i\ \/BBCAL_CS3\/IPROBE_CS2\/PLUS\;\ tran\ \(I\) = itime('tran "/BBCAL_CS3/IPROBE_CS2/PLUS")
plot( i\ \/BBCAL_CS3\/IPROBE_CS2\/PLUS\;\ tran\ \(I\) ?expr '( "i /BBCAL_CS3/IPROBE_CS2/PLUS; tran (I)" ) )
snapshot\:DCSW6_Ierr_total = (average(clip(IT("/DCSW6_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 2))
plot( snapshot\:DCSW6_Ierr_total ?expr '( "snapshot:DCSW6_Ierr_total" ) )
v\ \/BBCAL_CS3\/CS3_RESET_L_int\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/CS3_RESET_L_int")
plot( v\ \/BBCAL_CS3\/CS3_RESET_L_int\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/CS3_RESET_L_int; tran (V)" ) )
DC\:CS6_V_source1_int_node = VDC("/BBCAL_CS6/source1_int_node_0V45")
plot( DC\:CS6_V_source1_int_node ?expr '( "DC:CS6_V_source1_int_node" ) )
tran\:Ierr_CS3 = (IT("/IOUT_PROBE_CS3/PLUS") - 2.5e-06)
plot( tran\:Ierr_CS3 ?expr '( "tran:Ierr_CS3" ) )
i\ \/BBCAL_CS1\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) = (32 * itime('tran "/BBCAL_CS1/IPROBE_CS1/PLUS"))
plot( i\ \/BBCAL_CS1\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) ?expr '( "i /BBCAL_CS1/IPROBE_CS1/PLUS; tran (I)" ) )
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#3 = 0
plot( \#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#3 ?expr '( "#############################3" ) )
DC\:CS1_V_source2_int_node = VDC("/BBCAL_CS1/source2_int_node_0V45")
plot( DC\:CS1_V_source2_int_node ?expr '( "DC:CS1_V_source2_int_node" ) )
DC\:CS4_V_source1_int_node = VDC("/BBCAL_CS4/source1_int_node_0V45")
plot( DC\:CS4_V_source1_int_node ?expr '( "DC:CS4_V_source1_int_node" ) )
tran\:Ierr_CS1 = (IT("/IOUT_PROBE_CS1/PLUS") - 6.25e-07)
plot( tran\:Ierr_CS1 ?expr '( "tran:Ierr_CS1" ) )
snapshot\:DCSW5_Ierr_total = (average(clip(IT("/DCSW5_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 4))
plot( snapshot\:DCSW5_Ierr_total ?expr '( "snapshot:DCSW5_Ierr_total" ) )
i\ \/V4\/MINUS\;\ dc\ \(I\) = i("/V4/MINUS" ?result "dc")
plot( i\ \/V4\/MINUS\;\ dc\ \(I\) ?expr '( "i /V4/MINUS; dc (I)" ) )
v\ \/BBCAL_CS3\/CS3_CAL_S2_L\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/CS3_CAL_S2_L")
plot( v\ \/BBCAL_CS3\/CS3_CAL_S2_L\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/CS3_CAL_S2_L; tran (V)" ) )
DC\:CS0_V_source1_int_node = VDC("/BBCAL_CS0/source1_int_node_0V45")
plot( DC\:CS0_V_source1_int_node ?expr '( "DC:CS0_V_source1_int_node" ) )
v\ \/BBCAL_CS3\/BULK_S1\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/BULK_S1")
plot( v\ \/BBCAL_CS3\/BULK_S1\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/BULK_S1; tran (V)" ) )
DC\:CS5_V_source1_int_node = VDC("/BBCAL_CS5/source1_int_node_0V45")
plot( DC\:CS5_V_source1_int_node ?expr '( "DC:CS5_V_source1_int_node" ) )
tran\:Ierr_CS2 = (IT("/IOUT_PROBE_CS2/PLUS") - 1.25e-06)
plot( tran\:Ierr_CS2 ?expr '( "tran:Ierr_CS2" ) )
snapshot\:CS5_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS5/PLUS") - (I_total / 4)) 1.1e-05 1.4e-05))
plot( snapshot\:CS5_Ierr_precal ?expr '( "snapshot:CS5_Ierr_precal" ) )
snapshot\:DCSW2_Ierr_total = (average(clip(IT("/DCSW2_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 32))
plot( snapshot\:DCSW2_Ierr_total ?expr '( "snapshot:DCSW2_Ierr_total" ) )
DC\:CS0_V_source2_int_node = VDC("/BBCAL_CS0/source2_int_node_0V45")
plot( DC\:CS0_V_source2_int_node ?expr '( "DC:CS0_V_source2_int_node" ) )
snapshot\:CS1_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS1/PLUS") - (I_total / 64)) 1.1e-05 1.4e-05))
plot( snapshot\:CS1_Ierr_precal ?expr '( "snapshot:CS1_Ierr_precal" ) )
snapshot\:CS3_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS3/PLUS") - (I_total / 16)) 1.1e-05 1.4e-05))
plot( snapshot\:CS3_Ierr_precal ?expr '( "snapshot:CS3_Ierr_precal" ) )
snapshot\:CS4_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS4/PLUS") - (I_total / 8)) 1.1e-05 1.4e-05))
plot( snapshot\:CS4_Ierr_precal ?expr '( "snapshot:CS4_Ierr_precal" ) )
v\ \/BBCAL_CS3\/CS3_CON_S2_L\;\ tran\ \(V\) = vtime('tran "/BBCAL_CS3/CS3_CON_S2_L")
plot( v\ \/BBCAL_CS3\/CS3_CON_S2_L\;\ tran\ \(V\) ?expr '( "v /BBCAL_CS3/CS3_CON_S2_L; tran (V)" ) )
DC\:CS5_V_source2_int_node = VDC("/BBCAL_CS5/source2_int_node_0V45")
plot( DC\:CS5_V_source2_int_node ?expr '( "DC:CS5_V_source2_int_node" ) )
snapshot\:DCSW3_Ierr_total = (average(clip(IT("/DCSW3_PROBE_IOUTP/MINUS") 9.5e-05 0.000195)) - (I_total / 16))
plot( snapshot\:DCSW3_Ierr_total ?expr '( "snapshot:DCSW3_Ierr_total" ) )
i\ \/IOUT_PROBE_CS0\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS0/PLUS")
plot( i\ \/IOUT_PROBE_CS0\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS0/PLUS; tran (I)" ) )
i\ \/BBCAL_CS2\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) = (16 * itime('tran "/BBCAL_CS2/IPROBE_CS1/PLUS"))
plot( i\ \/BBCAL_CS2\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) ?expr '( "i /BBCAL_CS2/IPROBE_CS1/PLUS; tran (I)" ) )
tran\:Ierr_CS6 = (IT("/IOUT_PROBE_CS6/PLUS") - 2e-05)
plot( tran\:Ierr_CS6 ?expr '( "tran:Ierr_CS6" ) )
snapshot\:CS5_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS5/PLUS") - (I_total / 4)) 9.6e-05 9.9e-05))
plot( snapshot\:CS5_Ierr_postcal ?expr '( "snapshot:CS5_Ierr_postcal" ) )
i\ \/IOUT_PROBE_CS2\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS2/PLUS")
plot( i\ \/IOUT_PROBE_CS2\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS2/PLUS; tran (I)" ) )
i\ \/BBCAL_CS0\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) = (64 * itime('tran "/BBCAL_CS0/IPROBE_CS1/PLUS"))
plot( i\ \/BBCAL_CS0\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) ?expr '( "i /BBCAL_CS0/IPROBE_CS1/PLUS; tran (I)" ) )
snapshot\:CS2_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS2/PLUS") - (I_total / 32)) 9.6e-05 9.9e-05))
plot( snapshot\:CS2_Ierr_postcal ?expr '( "snapshot:CS2_Ierr_postcal" ) )
snapshot\:CS1_Ierr_postcal = average(clip((IT("/IOUT_PROBE_CS1/PLUS") - (I_total / 64)) 9.6e-05 9.9e-05))
plot( snapshot\:CS1_Ierr_postcal ?expr '( "snapshot:CS1_Ierr_postcal" ) )
snapshot\:CS6_Ierr_precal = average(clip((IT("/IOUT_PROBE_CS6/PLUS") - (I_total / 2)) 1.1e-05 1.4e-05))
plot( snapshot\:CS6_Ierr_precal ?expr '( "snapshot:CS6_Ierr_precal" ) )
i\ \/BBCAL_CS3\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) = (8 * itime('tran "/BBCAL_CS3/IPROBE_CS1/PLUS"))
plot( i\ \/BBCAL_CS3\/IPROBE_CS1\/PLUS\;\ tran\ \(I\) ?expr '( "i /BBCAL_CS3/IPROBE_CS1/PLUS; tran (I)" ) )
i\ \/IOUT_PROBE_CS6\/PLUS\;\ tran\ \(I\) = itime('tran "/IOUT_PROBE_CS6/PLUS")
plot( i\ \/IOUT_PROBE_CS6\/PLUS\;\ tran\ \(I\) ?expr '( "i /IOUT_PROBE_CS6/PLUS; tran (I)" ) )
plot( VDC("/net051") )
plot( IDC("/N19/d") )
plot( VDC("/Vb_cal") )
plot( VDC("/source_ref_in") )
plot( VDC("/cs_outnet") )
plot( VDC("/cm_innet") )
plot( (64 * IT("/IOUT_PROBE_CS0/PLUS")) )
plot( (32 * IT("/IOUT_PROBE_CS1/PLUS")) )
plot( (16 * IT("/IOUT_PROBE_CS2/PLUS")) )
plot( (8 * IT("/IOUT_PROBE_CS3/PLUS")) )
plot( (4 * IT("/IOUT_PROBE_CS4/PLUS")) )
plot( (2 * IT("/IOUT_PROBE_CS5/PLUS")) )
plot( (1 * IT("/IOUT_PROBE_CS6/PLUS")) )

Fullscreen 4721.spectre.out.txt Download

Global user options:
      ignorezerovar = yes
         psfversion = 1.1.0
            vabstol = 1e-06
            iabstol = 1e-12
               temp = 100
               gmin = 1e-12
             rforce = 1
             vthmod = vthcc
              ivthn = 3e-07
              ivthp = 7e-08
              ivthw = 0
              ivthl = 0
           maxnotes = 5
           maxwarns = 5
             digits = 5
               cols = 80
            pivotdc = yes
     dc_pivot_check = yes
             pivrel = 0.001
           sensfile = ../psf/sens.output
     checklimitdest = psf
           vdsatmod = gds
               save = lvlpub
            nestlvl = 2
           currents = selected
             reltol = 0.001
               tnom = 27

Scoped user options:

Circuit inventory:
              nodes 9575
            bsimimg 1830  
     bsource_3a7f1b 546   
bsource_resnoise_r_d794c7 72    
          capacitor 7694  
       counter_6bit 1     
              diode 728   
            isource 2     
           resistor 6395  
            vsource 351   
          juncap200 16    

Analysis and control statement inventory:
                 dc 1     
               info 8     
               tran 1     

Output statements:
             .probe 0     
           .measure 0     
               save 1     


Notice from spectre during initial setup.
    4 resistors are shorted because their absolute value is less than or equal to 'rabsshort'.
    223 vsources are short because their absolute value is less than or equal to 'vabsshort'.
    Fast APS Enabled.
    5 notices suppressed.
    669 warnings suppressed.
    Multithreading Enabled: 16 threads in the system with 16 available processors.

Time for parsing: CPU = 879.866 ms, elapsed = 930.785 ms.
Time accumulated: CPU = 3.9584 s, elapsed = 5.3752 s.
Peak resident memory used = 213 Mbytes.

~~~~~~~~~~~~~~~~~~~~~~
Pre-Simulation Summary
~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~

******************
DC Analysis `dcOp'
******************

Opening the PSF file ../psf/dcOp.dc ...
Important parameter values:
    reltol = 1e-03
    abstol(V) = 1 uV
    abstol(I) = 1 pA
    temp = 100 C
    tnom = 27 C
    tempeffects = all
    gmindc = 1 pS
    rabsshort = 1 mOhm
Trying `homotopy = gmin'.
Continuation method failed. Step size is too small.
Trying `homotopy = source'.
Trying `homotopy = dptran'.

Maximum value achieved for any signal of each quantity: 
V: V(LSBREF.R56.8) = 2.84 V
I: I(V2:p) = 1.055 mA
Convergence achieved in 1566 iterations.
DC simulation time: CPU = 40.3899 s, elapsed = 15.3254 s.
Total time required for dc analysis `dcOp': CPU = 40.3999 s, elapsed = 15.3346 s.
Time accumulated: CPU = 44.3683 s, elapsed = 20.7189 s.
Peak resident memory used = 224 Mbytes.

dcOpInfo: writing operating point information to rawfile.

Opening the PSF file ../psf/dcOpInfo.info ...

Notice from spectre during transient analysis `tran'.
    Specified 'noisefmin' is smaller than 1/stop time. 'noisefmin' has been changed to 1 MHz.


***********************************************
Transient Analysis `tran': time = (0 s -> 1 us)
***********************************************
DC simulation time: CPU = 272.959 ms, elapsed = 127.435 ms.

Opening the PSFXL file ../psf/tran.tran.tran ...
Important parameter values:
    start = 0 s
    outputstart = 0 s
    stop = 1 us
    step = 1 ns
    maxstep = 10 ns
    ic = all
    useprevic = no
    skipdc = no
    reltol = 100e-06
    abstol(V) = 1 uV
    abstol(I) = 1 pA
    temp = 100 C
    tnom = 27 C
    tempeffects = all
    errpreset = conservative_sigglobal
    method = gear2only
    lteratio = 10
    relref = sigglobal
    cmin = 0 F
    gmin = 1 pS
    rabsshort = 1 mOhm
    trannoisemethod = default
    noisefmax = 10 GHz
    noisefmin = 1 MHz
    noiseseed = 47


Output and IC/nodeset summary:
                 save   32      (current)
                 save   473     (voltage)

    tran: time = 2.5 ns      (250 m%), step = 25 ps        (2.5 m%)
    tran: time = 5.2 ns      (520 m%), step = 25 ps        (2.5 m%)
    tran: time = 7.575 ns    (757 m%), step = 25 ps        (2.5 m%)
    tran: time = 9.475 ns    (947 m%), step = 25 ps        (2.5 m%)
    tran: time = 11.6 ns     (1.16 %), step = 25 ps        (2.5 m%)
    tran: time = 14.13 ns    (1.41 %), step = 25 ps        (2.5 m%)
    tran: time = 16.9 ns     (1.69 %), step = 25 ps        (2.5 m%)
    tran: time = 19.43 ns    (1.94 %), step = 25 ps        (2.5 m%)
    tran: time = 21.85 ns    (2.19 %), step = 25 ps        (2.5 m%)
    tran: time = 23.18 ns    (2.32 %), step = 25 ps        (2.5 m%)
    tran: time = 24.95 ns     (2.5 %), step = 25 ps        (2.5 m%)
    tran: time = 25 ns        (2.5 %), step = 25 ps        (2.5 m%)
    tran: time = 26.95 ns     (2.7 %), step = 25 ps        (2.5 m%)
    tran: time = 29.43 ns    (2.94 %), step = 25 ps        (2.5 m%)
    tran: time = 31.68 ns    (3.17 %), step = 25 ps        (2.5 m%)
    tran: time = 35.07 ns    (3.51 %), step = 25 ps        (2.5 m%)
    tran: time = 38.4 ns     (3.84 %), step = 25 ps        (2.5 m%)
    tran: time = 41.3 ns     (4.13 %), step = 25 ps        (2.5 m%)
    tran: time = 44.37 ns    (4.44 %), step = 25 ps        (2.5 m%)
    tran: time = 47.6 ns     (4.76 %), step = 25 ps        (2.5 m%)
    tran: time = 51.07 ns    (5.11 %), step = 25 ps        (2.5 m%)
    tran: time = 53.85 ns    (5.38 %), step = 25 ps        (2.5 m%)
    tran: time = 56.77 ns    (5.68 %), step = 25 ps        (2.5 m%)
    tran: time = 59.45 ns    (5.94 %), step = 25 ps        (2.5 m%)
    tran: time = 61.62 ns    (6.16 %), step = 25 ps        (2.5 m%)
    tran: time = 65 ns        (6.5 %), step = 25 ps        (2.5 m%)
    tran: time = 68.52 ns    (6.85 %), step = 25 ps        (2.5 m%)
    tran: time = 70.95 ns    (7.09 %), step = 25 ps        (2.5 m%)
    tran: time = 72.48 ns    (7.25 %), step = 29.78 ps    (2.98 m%)
    tran: time = 73.47 ns    (7.35 %), step = 25 ps        (2.5 m%)
    tran: time = 74.07 ns    (7.41 %), step = 25 ps        (2.5 m%)
    tran: time = 75.02 ns     (7.5 %), step = 25 ps        (2.5 m%)
    tran: time = 77.55 ns    (7.75 %), step = 25 ps        (2.5 m%)
    tran: time = 80.55 ns    (8.06 %), step = 25 ps        (2.5 m%)
    tran: time = 82.78 ns    (8.28 %), step = 25 ps        (2.5 m%)
    tran: time = 85.28 ns    (8.53 %), step = 25 ps        (2.5 m%)
    tran: time = 87.2 ns     (8.72 %), step = 25 ps        (2.5 m%)
    tran: time = 87.9 ns     (8.79 %), step = 25 ps        (2.5 m%)
    tran: time = 89.2 ns     (8.92 %), step = 25 ps        (2.5 m%)
    tran: time = 91.15 ns    (9.12 %), step = 25 ps        (2.5 m%)
    tran: time = 94.35 ns    (9.44 %), step = 25 ps        (2.5 m%)
    tran: time = 95.38 ns    (9.54 %), step = 25 ps        (2.5 m%)
    tran: time = 96.9 ns     (9.69 %), step = 25 ps        (2.5 m%)
    tran: time = 98.9 ns     (9.89 %), step = 25 ps        (2.5 m%)
    tran: time = 100.2 ns      (10 %), step = 25 ps        (2.5 m%)
    tran: time = 100.3 ns      (10 %), step = 25 ps        (2.5 m%)
    tran: time = 101.5 ns    (10.2 %), step = 25 ps        (2.5 m%)
    tran: time = 101.9 ns    (10.2 %), step = 25 ps        (2.5 m%)
    tran: time = 102.1 ns    (10.2 %), step = 25 ps        (2.5 m%)
    tran: time = 102.3 ns    (10.2 %), step = 25 ps        (2.5 m%)
    tran: time = 102.5 ns    (10.2 %), step = 25 ps        (2.5 m%)
    tran: time = 102.5 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 102.7 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 102.7 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 102.9 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 103.1 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 103.2 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 103.4 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 103.5 ns    (10.3 %), step = 25 ps        (2.5 m%)
    tran: time = 103.7 ns    (10.4 %), step = 25 ps        (2.5 m%)
    tran: time = 105.6 ns    (10.6 %), step = 25 ps        (2.5 m%)
    tran: time = 107.2 ns    (10.7 %), step = 25 ps        (2.5 m%)
    tran: time = 109 ns      (10.9 %), step = 25 ps        (2.5 m%)
    tran: time = 111.5 ns    (11.2 %), step = 25 ps        (2.5 m%)
    tran: time = 113.9 ns    (11.4 %), step = 25 ps        (2.5 m%)
    tran: time = 114.7 ns    (11.5 %), step = 25 ps        (2.5 m%)
    tran: time = 114.8 ns    (11.5 %), step = 25 ps        (2.5 m%)
    tran: time = 115.3 ns    (11.5 %), step = 25 ps        (2.5 m%)
    tran: time = 116 ns      (11.6 %), step = 25 ps        (2.5 m%)
    tran: time = 116.8 ns    (11.7 %), step = 25 ps        (2.5 m%)
    tran: time = 117.8 ns    (11.8 %), step = 25 ps        (2.5 m%)
    tran: time = 118.9 ns    (11.9 %), step = 25 ps        (2.5 m%)
    tran: time = 121.1 ns    (12.1 %), step = 25 ps        (2.5 m%)
    tran: time = 122.6 ns    (12.3 %), step = 7.346 ps     (735 u%)
    tran: time = 124.5 ns    (12.4 %), step = 27.9 ps     (2.79 m%)
    tran: time = 125 ns      (12.5 %), step = 25 ps        (2.5 m%)
    tran: time = 128.5 ns    (12.8 %), step = 25 ps        (2.5 m%)
    tran: time = 131.4 ns    (13.1 %), step = 25 ps        (2.5 m%)
    tran: time = 133.6 ns    (13.4 %), step = 25 ps        (2.5 m%)
    tran: time = 135.8 ns    (13.6 %), step = 25 ps        (2.5 m%)
    tran: time = 138.7 ns    (13.9 %), step = 25 ps        (2.5 m%)
    tran: time = 143 ns      (14.3 %), step = 25 ps        (2.5 m%)
    tran: time = 145.2 ns    (14.5 %), step = 25 ps        (2.5 m%)
    tran: time = 148.7 ns    (14.9 %), step = 25 ps        (2.5 m%)
    tran: time = 152.4 ns    (15.2 %), step = 25 ps        (2.5 m%)
    tran: time = 156.5 ns    (15.6 %), step = 25 ps        (2.5 m%)
    tran: time = 161.2 ns    (16.1 %), step = 25 ps        (2.5 m%)
    tran: time = 164.3 ns    (16.4 %), step = 25 ps        (2.5 m%)
    tran: time = 167.6 ns    (16.8 %), step = 25 ps        (2.5 m%)
    tran: time = 170.2 ns      (17 %), step = 25 ps        (2.5 m%)
    tran: time = 173.5 ns    (17.3 %), step = 29 ps        (2.9 m%)
    tran: time = 175 ns      (17.5 %), step = 25 ps        (2.5 m%)
    tran: time = 178.6 ns    (17.9 %), step = 25 ps        (2.5 m%)
    tran: time = 181 ns      (18.1 %), step = 25 ps        (2.5 m%)
    tran: time = 183.9 ns    (18.4 %), step = 25 ps        (2.5 m%)
    tran: time = 186.7 ns    (18.7 %), step = 25 ps        (2.5 m%)
    tran: time = 188.9 ns    (18.9 %), step = 25 ps        (2.5 m%)
    tran: time = 191.1 ns    (19.1 %), step = 25 ps        (2.5 m%)
    tran: time = 194.3 ns    (19.4 %), step = 25 ps        (2.5 m%)
    tran: time = 196.2 ns    (19.6 %), step = 15.63 ps    (1.56 m%)
    tran: time = 199.1 ns    (19.9 %), step = 25 ps        (2.5 m%)
    tran: time = 201.2 ns    (20.1 %), step = 25 ps        (2.5 m%)
    tran: time = 204.1 ns    (20.4 %), step = 25 ps        (2.5 m%)
    tran: time = 207.8 ns    (20.8 %), step = 25 ps        (2.5 m%)
    tran: time = 211.3 ns    (21.1 %), step = 25 ps        (2.5 m%)
    tran: time = 213.2 ns    (21.3 %), step = 25 ps        (2.5 m%)
    tran: time = 215.7 ns    (21.6 %), step = 25 ps        (2.5 m%)
    tran: time = 220 ns        (22 %), step = 25 ps        (2.5 m%)
    tran: time = 222.7 ns    (22.3 %), step = 26.72 ps    (2.67 m%)
    tran: time = 224.8 ns    (22.5 %), step = 25 ps        (2.5 m%)
    tran: time = 225 ns      (22.5 %), step = 25 ps        (2.5 m%)
    tran: time = 228.7 ns    (22.9 %), step = 25 ps        (2.5 m%)
    tran: time = 229.7 ns      (23 %), step = 25 ps        (2.5 m%)
    tran: time = 230.8 ns    (23.1 %), step = 25 ps        (2.5 m%)
    tran: time = 232.2 ns    (23.2 %), step = 6.25 ps      (625 u%)
    tran: time = 235.7 ns    (23.6 %), step = 25 ps        (2.5 m%)
    tran: time = 236.1 ns    (23.6 %), step = 25 ps        (2.5 m%)
    tran: time = 236.4 ns    (23.6 %), step = 25 ps        (2.5 m%)
    tran: time = 238.5 ns    (23.9 %), step = 25 ps        (2.5 m%)
    tran: time = 240.7 ns    (24.1 %), step = 25 ps        (2.5 m%)
    tran: time = 243.2 ns    (24.3 %), step = 25 ps        (2.5 m%)
    tran: time = 244 ns      (24.4 %), step = 25 ps        (2.5 m%)
    tran: time = 245.2 ns    (24.5 %), step = 25 ps        (2.5 m%)
    tran: time = 246.9 ns    (24.7 %), step = 25 ps        (2.5 m%)
    tran: time = 248 ns      (24.8 %), step = 25 ps        (2.5 m%)
    tran: time = 249.1 ns    (24.9 %), step = 25 ps        (2.5 m%)
    tran: time = 250.1 ns      (25 %), step = 25 ps        (2.5 m%)
    tran: time = 251.8 ns    (25.2 %), step = 25 ps        (2.5 m%)
    tran: time = 253.4 ns    (25.3 %), step = 25 ps        (2.5 m%)
    tran: time = 254.7 ns    (25.5 %), step = 25 ps        (2.5 m%)
    tran: time = 256.6 ns    (25.7 %), step = 25 ps        (2.5 m%)
    tran: time = 258.1 ns    (25.8 %), step = 25 ps        (2.5 m%)
    tran: time = 258.6 ns    (25.9 %), step = 25 ps        (2.5 m%)
    tran: time = 258.9 ns    (25.9 %), step = 25 ps        (2.5 m%)
    tran: time = 259.3 ns    (25.9 %), step = 25 ps        (2.5 m%)
    tran: time = 260.3 ns      (26 %), step = 25 ps        (2.5 m%)
    tran: time = 264.1 ns    (26.4 %), step = 25 ps        (2.5 m%)
    tran: time = 268.3 ns    (26.8 %), step = 25 ps        (2.5 m%)
    tran: time = 273.1 ns    (27.3 %), step = 25 ps        (2.5 m%)
    tran: time = 275 ns      (27.5 %), step = 25 ps        (2.5 m%)
    tran: time = 277.9 ns    (27.8 %), step = 25 ps        (2.5 m%)
    tran: time = 280.8 ns    (28.1 %), step = 25 ps        (2.5 m%)
    tran: time = 283.6 ns    (28.4 %), step = 25 ps        (2.5 m%)
    tran: time = 286.2 ns    (28.6 %), step = 25 ps        (2.5 m%)
    tran: time = 290.5 ns    (29.1 %), step = 25 ps        (2.5 m%)
    tran: time = 295 ns      (29.5 %), step = 25 ps        (2.5 m%)
    tran: time = 297.5 ns    (29.7 %), step = 25 ps        (2.5 m%)
    tran: time = 299.2 ns    (29.9 %), step = 25 ps        (2.5 m%)
    tran: time = 302.4 ns    (30.2 %), step = 25 ps        (2.5 m%)
    tran: time = 305.3 ns    (30.5 %), step = 25 ps        (2.5 m%)
    tran: time = 306.6 ns    (30.7 %), step = 25 ps        (2.5 m%)
    tran: time = 308.4 ns    (30.8 %), step = 25 ps        (2.5 m%)
    tran: time = 309.7 ns      (31 %), step = 25 ps        (2.5 m%)
    tran: time = 311.4 ns    (31.1 %), step = 25 ps        (2.5 m%)
    tran: time = 314.6 ns    (31.5 %), step = 15.62 ps    (1.56 m%)
    tran: time = 316.7 ns    (31.7 %), step = 25 ps        (2.5 m%)
    tran: time = 320.5 ns      (32 %), step = 25 ps        (2.5 m%)
    tran: time = 323.2 ns    (32.3 %), step = 25 ps        (2.5 m%)
    tran: time = 325 ns      (32.5 %), step = 25 ps        (2.5 m%)
    tran: time = 327 ns      (32.7 %), step = 25 ps        (2.5 m%)
    tran: time = 331.1 ns    (33.1 %), step = 25 ps        (2.5 m%)
    tran: time = 335.9 ns    (33.6 %), step = 25 ps        (2.5 m%)
    tran: time = 339.6 ns      (34 %), step = 25 ps        (2.5 m%)
    tran: time = 342.3 ns    (34.2 %), step = 25 ps        (2.5 m%)
    tran: time = 344.4 ns    (34.4 %), step = 25 ps        (2.5 m%)
    tran: time = 346.1 ns    (34.6 %), step = 25 ps        (2.5 m%)
    tran: time = 348.1 ns    (34.8 %), step = 25 ps        (2.5 m%)
    tran: time = 350.1 ns      (35 %), step = 25 ps        (2.5 m%)
    tran: time = 353.1 ns    (35.3 %), step = 25 ps        (2.5 m%)
    tran: time = 356.8 ns    (35.7 %), step = 25 ps        (2.5 m%)
    tran: time = 360.2 ns      (36 %), step = 25 ps        (2.5 m%)
    tran: time = 362.6 ns    (36.3 %), step = 25 ps        (2.5 m%)
    tran: time = 364.4 ns    (36.4 %), step = 25 ps        (2.5 m%)
    tran: time = 365.5 ns    (36.6 %), step = 25 ps        (2.5 m%)
    tran: time = 368.1 ns    (36.8 %), step = 25 ps        (2.5 m%)
    tran: time = 369 ns      (36.9 %), step = 25 ps        (2.5 m%)
    tran: time = 373.1 ns    (37.3 %), step = 25 ps        (2.5 m%)
    tran: time = 375 ns      (37.5 %), step = 25 ps        (2.5 m%)
    tran: time = 378.5 ns    (37.8 %), step = 25 ps        (2.5 m%)
    tran: time = 384 ns      (38.4 %), step = 25 ps        (2.5 m%)
    tran: time = 388.3 ns    (38.8 %), step = 25 ps        (2.5 m%)
    tran: time = 391.5 ns    (39.1 %), step = 25 ps        (2.5 m%)
    tran: time = 395.5 ns    (39.6 %), step = 25 ps        (2.5 m%)
    tran: time = 400.6 ns    (40.1 %), step = 25 ps        (2.5 m%)
    tran: time = 404.1 ns    (40.4 %), step = 25 ps        (2.5 m%)
    tran: time = 406.9 ns    (40.7 %), step = 25 ps        (2.5 m%)
    tran: time = 411.5 ns    (41.1 %), step = 25 ps        (2.5 m%)
    tran: time = 415.2 ns    (41.5 %), step = 25 ps        (2.5 m%)
    tran: time = 419.2 ns    (41.9 %), step = 25 ps        (2.5 m%)
    tran: time = 424.1 ns    (42.4 %), step = 25 ps        (2.5 m%)
    tran: time = 425 ns      (42.5 %), step = 25 ps        (2.5 m%)
    tran: time = 430.2 ns      (43 %), step = 25 ps        (2.5 m%)
    tran: time = 434.6 ns    (43.5 %), step = 25 ps        (2.5 m%)
    tran: time = 438.5 ns    (43.8 %), step = 25 ps        (2.5 m%)
    tran: time = 440.4 ns      (44 %), step = 25 ps        (2.5 m%)
    tran: time = 443.8 ns    (44.4 %), step = 25 ps        (2.5 m%)
    tran: time = 447.6 ns    (44.8 %), step = 25 ps        (2.5 m%)
    tran: time = 451 ns      (45.1 %), step = 25 ps        (2.5 m%)
    tran: time = 455.1 ns    (45.5 %), step = 25 ps        (2.5 m%)
    tran: time = 459 ns      (45.9 %), step = 25 ps        (2.5 m%)
    tran: time = 462.4 ns    (46.2 %), step = 25 ps        (2.5 m%)
    tran: time = 466.7 ns    (46.7 %), step = 25 ps        (2.5 m%)
    tran: time = 469 ns      (46.9 %), step = 25 ps        (2.5 m%)
    tran: time = 472 ns      (47.2 %), step = 21.76 ps    (2.18 m%)
    tran: time = 475 ns      (47.5 %), step = 25 ps        (2.5 m%)
    tran: time = 478.2 ns    (47.8 %), step = 25 ps        (2.5 m%)
    tran: time = 481 ns      (48.1 %), step = 25 ps        (2.5 m%)
    tran: time = 481.4 ns    (48.1 %), step = 25 ps        (2.5 m%)
    tran: time = 481.9 ns    (48.2 %), step = 25 ps        (2.5 m%)
    tran: time = 484.3 ns    (48.4 %), step = 25 ps        (2.5 m%)
    tran: time = 487 ns      (48.7 %), step = 25 ps        (2.5 m%)
    tran: time = 488.2 ns    (48.8 %), step = 25 ps        (2.5 m%)
    tran: time = 492.2 ns    (49.2 %), step = 25 ps        (2.5 m%)
    tran: time = 495.7 ns    (49.6 %), step = 25 ps        (2.5 m%)
    tran: time = 498.8 ns    (49.9 %), step = 25 ps        (2.5 m%)
    tran: time = 500.7 ns    (50.1 %), step = 25 ps        (2.5 m%)
    tran: time = 504.2 ns    (50.4 %), step = 25 ps        (2.5 m%)
    tran: time = 508.5 ns    (50.8 %), step = 25 ps        (2.5 m%)
    tran: time = 512.7 ns    (51.3 %), step = 25 ps        (2.5 m%)
    tran: time = 515.5 ns    (51.5 %), step = 20.32 ps    (2.03 m%)
    tran: time = 518.7 ns    (51.9 %), step = 25 ps        (2.5 m%)
    tran: time = 520.5 ns    (52.1 %), step = 25 ps        (2.5 m%)
    tran: time = 523.3 ns    (52.3 %), step = 25 ps        (2.5 m%)
    tran: time = 525 ns      (52.5 %), step = 25 ps        (2.5 m%)
    tran: time = 527.8 ns    (52.8 %), step = 25 ps        (2.5 m%)
    tran: time = 530.2 ns      (53 %), step = 25 ps        (2.5 m%)
    tran: time = 531.8 ns    (53.2 %), step = 25 ps        (2.5 m%)
    tran: time = 534.2 ns    (53.4 %), step = 25 ps        (2.5 m%)
    tran: time = 536.2 ns    (53.6 %), step = 25 ps        (2.5 m%)
    tran: time = 538.4 ns    (53.8 %), step = 25 ps        (2.5 m%)
    tran: time = 541.1 ns    (54.1 %), step = 25 ps        (2.5 m%)
    tran: time = 544.3 ns    (54.4 %), step = 25 ps        (2.5 m%)
    tran: time = 547.9 ns    (54.8 %), step = 29.22 ps    (2.92 m%)
    tran: time = 552.2 ns    (55.2 %), step = 25 ps        (2.5 m%)
    tran: time = 553.9 ns    (55.4 %), step = 25 ps        (2.5 m%)
    tran: time = 557.6 ns    (55.8 %), step = 25 ps        (2.5 m%)
    tran: time = 562.5 ns    (56.2 %), step = 25 ps        (2.5 m%)
    tran: time = 565.6 ns    (56.6 %), step = 25 ps        (2.5 m%)
    tran: time = 568.6 ns    (56.9 %), step = 25 ps        (2.5 m%)
    tran: time = 570.6 ns    (57.1 %), step = 25 ps        (2.5 m%)
    tran: time = 574.1 ns    (57.4 %), step = 25 ps        (2.5 m%)
    tran: time = 575 ns      (57.5 %), step = 25 ps        (2.5 m%)
    tran: time = 577 ns      (57.7 %), step = 25 ps        (2.5 m%)
    tran: time = 579.9 ns      (58 %), step = 25 ps        (2.5 m%)
    tran: time = 584.1 ns    (58.4 %), step = 25 ps        (2.5 m%)
    tran: time = 587.3 ns    (58.7 %), step = 25 ps        (2.5 m%)
    tran: time = 590.2 ns      (59 %), step = 25 ps        (2.5 m%)
    tran: time = 592.3 ns    (59.2 %), step = 6.25 ps      (625 u%)
    tran: time = 593.6 ns    (59.4 %), step = 25 ps        (2.5 m%)
    tran: time = 595.1 ns    (59.5 %), step = 25 ps        (2.5 m%)
    tran: time = 596.8 ns    (59.7 %), step = 25 ps        (2.5 m%)
    tran: time = 599.1 ns    (59.9 %), step = 25 ps        (2.5 m%)
    tran: time = 600.7 ns    (60.1 %), step = 25 ps        (2.5 m%)
    tran: time = 602.3 ns    (60.2 %), step = 25 ps        (2.5 m%)
    tran: time = 603.9 ns    (60.4 %), step = 25 ps        (2.5 m%)
    tran: time = 606.6 ns    (60.7 %), step = 25 ps        (2.5 m%)
    tran: time = 608.4 ns    (60.8 %), step = 25 ps        (2.5 m%)
    tran: time = 610.7 ns    (61.1 %), step = 25 ps        (2.5 m%)
    tran: time = 612.3 ns    (61.2 %), step = 25 ps        (2.5 m%)
    tran: time = 614.6 ns    (61.5 %), step = 25 ps        (2.5 m%)
    tran: time = 616.5 ns    (61.6 %), step = 25 ps        (2.5 m%)
    tran: time = 619.5 ns    (61.9 %), step = 25 ps        (2.5 m%)
    tran: time = 622 ns      (62.2 %), step = 25 ps        (2.5 m%)
    tran: time = 623.8 ns    (62.4 %), step = 25 ps        (2.5 m%)
    tran: time = 624.5 ns    (62.4 %), step = 25 ps        (2.5 m%)
    tran: time = 625 ns      (62.5 %), step = 25 ps        (2.5 m%)
    tran: time = 626.4 ns    (62.6 %), step = 25 ps        (2.5 m%)
    tran: time = 627.8 ns    (62.8 %), step = 25 ps        (2.5 m%)
    tran: time = 629.3 ns    (62.9 %), step = 25 ps        (2.5 m%)
    tran: time = 632.4 ns    (63.2 %), step = 25 ps        (2.5 m%)
    tran: time = 635.3 ns    (63.5 %), step = 25 ps        (2.5 m%)
    tran: time = 637.5 ns    (63.8 %), step = 25 ps        (2.5 m%)
    tran: time = 640.1 ns      (64 %), step = 25 ps        (2.5 m%)
    tran: time = 643.4 ns    (64.3 %), step = 25 ps        (2.5 m%)
    tran: time = 646.2 ns    (64.6 %), step = 25 ps        (2.5 m%)
    tran: time = 649 ns      (64.9 %), step = 25 ps        (2.5 m%)
    tran: time = 650.7 ns    (65.1 %), step = 25 ps        (2.5 m%)
    tran: time = 653.3 ns    (65.3 %), step = 25 ps        (2.5 m%)
    tran: time = 655.1 ns    (65.5 %), step = 25 ps        (2.5 m%)
    tran: time = 659.5 ns      (66 %), step = 25 ps        (2.5 m%)
    tran: time = 661.1 ns    (66.1 %), step = 25 ps        (2.5 m%)
    tran: time = 663.6 ns    (66.4 %), step = 25 ps        (2.5 m%)
    tran: time = 668.3 ns    (66.8 %), step = 25 ps        (2.5 m%)
    tran: time = 673.5 ns    (67.3 %), step = 25 ps        (2.5 m%)
    tran: time = 675 ns      (67.5 %), step = 25 ps        (2.5 m%)
    tran: time = 679.6 ns      (68 %), step = 25 ps        (2.5 m%)
    tran: time = 684.2 ns    (68.4 %), step = 25 ps        (2.5 m%)
    tran: time = 688 ns      (68.8 %), step = 25 ps        (2.5 m%)
    tran: time = 692.8 ns    (69.3 %), step = 25 ps        (2.5 m%)
    tran: time = 697.6 ns    (69.8 %), step = 25 ps        (2.5 m%)
    tran: time = 702.4 ns    (70.2 %), step = 25 ps        (2.5 m%)
    tran: time = 706.6 ns    (70.7 %), step = 25 ps        (2.5 m%)
    tran: time = 710.5 ns      (71 %), step = 25 ps        (2.5 m%)
    tran: time = 715.4 ns    (71.5 %), step = 25 ps        (2.5 m%)
    tran: time = 720.3 ns      (72 %), step = 25 ps        (2.5 m%)
    tran: time = 725 ns      (72.5 %), step = 25 ps        (2.5 m%)
    tran: time = 725 ns      (72.5 %), step = 25 ps        (2.5 m%)
    tran: time = 729.8 ns      (73 %), step = 25 ps        (2.5 m%)
    tran: time = 734.6 ns    (73.5 %), step = 25 ps        (2.5 m%)
    tran: time = 738.8 ns    (73.9 %), step = 25 ps        (2.5 m%)
    tran: time = 743.4 ns    (74.3 %), step = 25 ps        (2.5 m%)
    tran: time = 748.1 ns    (74.8 %), step = 25 ps        (2.5 m%)
    tran: time = 753 ns      (75.3 %), step = 25 ps        (2.5 m%)
    tran: time = 757.5 ns    (75.8 %), step = 25 ps        (2.5 m%)
    tran: time = 761.7 ns    (76.2 %), step = 25 ps        (2.5 m%)
    tran: time = 766.2 ns    (76.6 %), step = 25 ps        (2.5 m%)
    tran: time = 770.2 ns      (77 %), step = 25 ps        (2.5 m%)
    tran: time = 774.3 ns    (77.4 %), step = 25 ps        (2.5 m%)
    tran: time = 775 ns      (77.5 %), step = 25 ps        (2.5 m%)
    tran: time = 779.2 ns    (77.9 %), step = 25 ps        (2.5 m%)
    tran: time = 783.2 ns    (78.3 %), step = 25 ps        (2.5 m%)
    tran: time = 786.3 ns    (78.6 %), step = 25 ps        (2.5 m%)
    tran: time = 790.6 ns    (79.1 %), step = 25 ps        (2.5 m%)
    tran: time = 794.5 ns    (79.5 %), step = 25 ps        (2.5 m%)
    tran: time = 797.7 ns    (79.8 %), step = 29.48 ps    (2.95 m%)
    tran: time = 802.2 ns    (80.2 %), step = 25 ps        (2.5 m%)
    tran: time = 807 ns      (80.7 %), step = 25 ps        (2.5 m%)
    tran: time = 811.5 ns    (81.2 %), step = 25 ps        (2.5 m%)
    tran: time = 816 ns      (81.6 %), step = 25 ps        (2.5 m%)
    tran: time = 820.8 ns    (82.1 %), step = 25 ps        (2.5 m%)
    tran: time = 825 ns      (82.5 %), step = 25 ps        (2.5 m%)
    tran: time = 828.5 ns    (82.9 %), step = 25 ps        (2.5 m%)
    tran: time = 830.4 ns      (83 %), step = 25 ps        (2.5 m%)
    tran: time = 832.2 ns    (83.2 %), step = 25 ps        (2.5 m%)
    tran: time = 834.2 ns    (83.4 %), step = 25 ps        (2.5 m%)
    tran: time = 835.9 ns    (83.6 %), step = 25 ps        (2.5 m%)
    tran: time = 838.4 ns    (83.8 %), step = 25 ps        (2.5 m%)
    tran: time = 839.6 ns      (84 %), step = 25 ps        (2.5 m%)
    tran: time = 841 ns      (84.1 %), step = 25 ps        (2.5 m%)
    tran: time = 842.6 ns    (84.3 %), step = 25 ps        (2.5 m%)
    tran: time = 844.4 ns    (84.4 %), step = 25 ps        (2.5 m%)
    tran: time = 846.8 ns    (84.7 %), step = 25 ps        (2.5 m%)
    tran: time = 849.2 ns    (84.9 %), step = 25 ps        (2.5 m%)
    tran: time = 851.1 ns    (85.1 %), step = 25 ps        (2.5 m%)
    tran: time = 852.7 ns    (85.3 %), step = 25 ps        (2.5 m%)
    tran: time = 854.4 ns    (85.4 %), step = 25 ps        (2.5 m%)
    tran: time = 856.1 ns    (85.6 %), step = 25 ps        (2.5 m%)
    tran: time = 857.1 ns    (85.7 %), step = 25 ps        (2.5 m%)
    tran: time = 858.3 ns    (85.8 %), step = 25 ps        (2.5 m%)
    tran: time = 860 ns        (86 %), step = 25 ps        (2.5 m%)
    tran: time = 861.6 ns    (86.2 %), step = 25 ps        (2.5 m%)
    tran: time = 862.5 ns    (86.3 %), step = 25 ps        (2.5 m%)
    tran: time = 862.6 ns    (86.3 %), step = 25 ps        (2.5 m%)
    tran: time = 863.3 ns    (86.3 %), step = 25 ps        (2.5 m%)
    tran: time = 864.4 ns    (86.4 %), step = 25 ps        (2.5 m%)
    tran: time = 865.5 ns    (86.6 %), step = 25 ps        (2.5 m%)
    tran: time = 867.3 ns    (86.7 %), step = 25 ps        (2.5 m%)
    tran: time = 868.8 ns    (86.9 %), step = 25 ps        (2.5 m%)
    tran: time = 870.5 ns    (87.1 %), step = 25 ps        (2.5 m%)
    tran: time = 872.5 ns    (87.2 %), step = 25 ps        (2.5 m%)
    tran: time = 874.3 ns    (87.4 %), step = 25 ps        (2.5 m%)
    tran: time = 875 ns      (87.5 %), step = 25 ps        (2.5 m%)
    tran: time = 877.3 ns    (87.7 %), step = 25 ps        (2.5 m%)
    tran: time = 879 ns      (87.9 %), step = 25 ps        (2.5 m%)
    tran: time = 881.2 ns    (88.1 %), step = 25 ps        (2.5 m%)
    tran: time = 882.7 ns    (88.3 %), step = 25 ps        (2.5 m%)
    tran: time = 885 ns      (88.5 %), step = 25 ps        (2.5 m%)
    tran: time = 886.5 ns    (88.7 %), step = 25 ps        (2.5 m%)
    tran: time = 888.1 ns    (88.8 %), step = 25 ps        (2.5 m%)
    tran: time = 890 ns        (89 %), step = 25 ps        (2.5 m%)
    tran: time = 891.7 ns    (89.2 %), step = 25 ps        (2.5 m%)
    tran: time = 894 ns      (89.4 %), step = 25 ps        (2.5 m%)
    tran: time = 896.4 ns    (89.6 %), step = 25 ps        (2.5 m%)
    tran: time = 898.1 ns    (89.8 %), step = 25 ps        (2.5 m%)
    tran: time = 900.1 ns      (90 %), step = 25 ps        (2.5 m%)
    tran: time = 902.1 ns    (90.2 %), step = 25 ps        (2.5 m%)
    tran: time = 904.7 ns    (90.5 %), step = 25 ps        (2.5 m%)
    tran: time = 906 ns      (90.6 %), step = 25 ps        (2.5 m%)
    tran: time = 907.6 ns    (90.8 %), step = 25 ps        (2.5 m%)
    tran: time = 909.9 ns      (91 %), step = 25 ps        (2.5 m%)
    tran: time = 911.8 ns    (91.2 %), step = 25 ps        (2.5 m%)
    tran: time = 913.4 ns    (91.3 %), step = 25 ps        (2.5 m%)
    tran: time = 915.9 ns    (91.6 %), step = 20.31 ps    (2.03 m%)
    tran: time = 918 ns      (91.8 %), step = 25 ps        (2.5 m%)
    tran: time = 920.3 ns      (92 %), step = 25 ps        (2.5 m%)
    tran: time = 921.8 ns    (92.2 %), step = 25 ps        (2.5 m%)
    tran: time = 923.7 ns    (92.4 %), step = 25 ps        (2.5 m%)
    tran: time = 925 ns      (92.5 %), step = 9.375 ps     (937 u%)
    tran: time = 926.5 ns    (92.6 %), step = 25 ps        (2.5 m%)
    tran: time = 928.5 ns    (92.8 %), step = 25 ps        (2.5 m%)
    tran: time = 930.6 ns    (93.1 %), step = 25 ps        (2.5 m%)
    tran: time = 932.4 ns    (93.2 %), step = 25 ps        (2.5 m%)
    tran: time = 934.3 ns    (93.4 %), step = 25 ps        (2.5 m%)
    tran: time = 936.1 ns    (93.6 %), step = 25 ps        (2.5 m%)
    tran: time = 937.9 ns    (93.8 %), step = 25 ps        (2.5 m%)
    tran: time = 939.8 ns      (94 %), step = 25 ps        (2.5 m%)
    tran: time = 941.9 ns    (94.2 %), step = 25 ps        (2.5 m%)
    tran: time = 943.4 ns    (94.3 %), step = 25 ps        (2.5 m%)
    tran: time = 946.2 ns    (94.6 %), step = 25 ps        (2.5 m%)
    tran: time = 947.7 ns    (94.8 %), step = 25 ps        (2.5 m%)
    tran: time = 949.3 ns    (94.9 %), step = 25 ps        (2.5 m%)
    tran: time = 951.5 ns    (95.2 %), step = 25 ps        (2.5 m%)
    tran: time = 953.7 ns    (95.4 %), step = 25 ps        (2.5 m%)
    tran: time = 955.5 ns    (95.6 %), step = 25 ps        (2.5 m%)
    tran: time = 957.6 ns    (95.8 %), step = 25 ps        (2.5 m%)
    tran: time = 959.6 ns      (96 %), step = 25 ps        (2.5 m%)
    tran: time = 961.5 ns    (96.1 %), step = 25 ps        (2.5 m%)
    tran: time = 963.5 ns    (96.3 %), step = 25 ps        (2.5 m%)
    tran: time = 965.5 ns    (96.6 %), step = 25 ps        (2.5 m%)
    tran: time = 967.3 ns    (96.7 %), step = 25 ps        (2.5 m%)
    tran: time = 970.2 ns      (97 %), step = 25 ps        (2.5 m%)
    tran: time = 972.6 ns    (97.3 %), step = 25 ps        (2.5 m%)
    tran: time = 974.6 ns    (97.5 %), step = 25 ps        (2.5 m%)
    tran: time = 975 ns      (97.5 %), step = 15.62 ps    (1.56 m%)
    tran: time = 977.5 ns    (97.7 %), step = 25 ps        (2.5 m%)
    tran: time = 979.2 ns    (97.9 %), step = 25 ps        (2.5 m%)
    tran: time = 981.5 ns    (98.1 %), step = 25 ps        (2.5 m%)
    tran: time = 982.5 ns    (98.3 %), step = 25 ps        (2.5 m%)
    tran: time = 984.4 ns    (98.4 %), step = 25 ps        (2.5 m%)
    tran: time = 986.5 ns    (98.6 %), step = 25 ps        (2.5 m%)
    tran: time = 988.1 ns    (98.8 %), step = 25 ps        (2.5 m%)
    tran: time = 989.8 ns      (99 %), step = 25 ps        (2.5 m%)
    tran: time = 991 ns      (99.1 %), step = 25 ps        (2.5 m%)
    tran: time = 992.3 ns    (99.2 %), step = 25 ps        (2.5 m%)
    tran: time = 993 ns      (99.3 %), step = 25 ps        (2.5 m%)
    tran: time = 994.1 ns    (99.4 %), step = 18.75 ps    (1.88 m%)
    tran: time = 995.8 ns    (99.6 %), step = 25 ps        (2.5 m%)
    tran: time = 997 ns      (99.7 %), step = 25 ps        (2.5 m%)
    tran: time = 999.1 ns    (99.9 %), step = 25 ps        (2.5 m%)
Number of accepted tran steps =             40783

Maximum value achieved for any signal of each quantity: 
V: V(LSBREF.Rupper_bit0.5) = 2.843 V
I: I(V2:p) = 8.305 mA
If your circuit contains signals of the same quantity that are vastly different in size (such as high voltage circuitry combined with low voltage control circuitry), you should consider specifying global option `bin_relref=yes'.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Post-Transient Simulation Summary
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   -   Non-default settings that could significantly slow down simulation
          errpreset = conservative_sigglobal, default moderate
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


During simulation, the CPU load for active processors is :
        Spectre  0 (70.7 %)      1 (76.4 %)      2 (76.0 %)      3 (77.1 %)
                 4 (78.7 %)      5 (72.8 %)      6 (69.8 %)      7 (63.4 %)
                 8 (67.8 %)      9 (67.7 %)     10 (56.3 %)     11 (54.7 %)
                12 (75.7 %)     13 (67.0 %)     14 (71.4 %)     15 (72.3 %)
        Other   
Initial condition solution time: CPU = 273.959 ms, elapsed = 131.696 ms.
Intrinsic tran analysis time:    CPU = 4.2521 ks, elapsed = 517.505 s.
Total time required for tran analysis `tran': CPU = 4.25246 ks (1h 10m 52s), elapsed = 517.697 s (8m  37.7s).
Time accumulated: CPU = 4.30152 ks (1h 11m 42s), elapsed = 539.162 s (8m  59.2s).
Peak resident memory used = 423 Mbytes.

finalTimeOP: writing operating point information to rawfile.

Opening the PSF file ../psf/finalTimeOP.info ...
modelParameter: writing model parameter values to rawfile.

Opening the PSF file ../psf/modelParameter.info ...
element: writing instance parameter values to rawfile.

Opening the PSF file ../psf/element.info ...
outputParameter: writing output parameter values to rawfile.

Opening the PSF file ../psf/outputParameter.info ...
designParamVals: writing netlist parameters to rawfile.

Opening the PSFASCII file ../psf/designParamVals.info ...
primitives: writing primitives to rawfile.

Opening the PSFASCII file ../psf/primitives.info.primitives ...
subckts: writing subcircuits to rawfile.

Opening the PSFASCII file ../psf/subckts.info.subckts ...

Aggregate audit (10:23:11 AM, Thur Sep 24, 2020):
Time used: CPU = 4.33 ks (1h 12m 7s), elapsed = 542 s (9m  1.7s), util. = 799%.
Time spent in licensing: elapsed = 78 ms.
Peak memory used = 423 Mbytes.
Simulation started at: 10:14:09 AM, Thur Sep 24, 2020, ended at: 10:23:11 AM, Thur Sep 24, 2020, with elapsed time (wall clock): 542 s (9m  1.7s).
spectre completes with 0 errors, 24 warnings, and 13 notices.


********* LOG ENDS **************
**                             **

ShawnLogan over 5 years ago in reply to Tobias Schirmer

Dear Tobius,

Thank you, very much, for including your spectre.out file and input.scs file! Both are extremely useful. Is it possible think the initial portion of the spectre.out file is missing? I expected to find the version information for Virtuoso and MMSIM and did not see it. I only mention this as there are often software fixes applied to specific versions that might pertain to your observed "simulation slowness".

I did take some time, nonetheless, to study both files in some detail. First, there are a number of items I noticed that suggest your methodology is basically sound - which is a credit to you as just setting up a transient noise simulation can be a challenge - good work!

A few comments follow for your thoughts...

1. I noticed your output log and transient noise statement has a simulation stop time of 1 us. The total simulation time (wall clock) is shown as about 9 minutes. In your original post, you noted your simulation stop time was 100 us. Did the simulation rate when the stop time was set to 100 us increase significantly from the rate of 1 us/9 min as the time increased to 100 us? In other words, did the simulation time seem to slow significantly as the simulation time increased beyond 1 us? This could be symptomatic of a different issue, and if so, the use of the +diagnose command line option can provide some good insight into this type of behavior.

2. The maximum integration time step is pegged at 25 ps. This is not totally consistent with your use of noisefmax=10 GHz. The maximum integration timestep should be set to 1/(2×noisefmax) = 1/20e9 = 50 ps. Hence, something else is limiting your maximum integration timestep. It is not your errpreset setting of "conservative" as this will set maxstep to TSTOP/100 = 1 us/100 = 10 ns. Hence, this is slowing down your simulation. I noticed a block "counter_6bit". If this is a veriloga module, is it compatible with a transient analysis? I am wondering if it might be reducing your maxstep from the expected value of 50 ps to 25 ps. If you have a circuit model for the block, it might be interesting to see if you replace the veriloga block with a circuit realization the maxstep value is increased to the expected value of 50 ps.

3. Since your maximum timestep will be set by noisefmax (or should be), I think you may be able to change your errpreset from "conservative" to "moderate" without a loss in simulation accuracy. In essence, your time steps are so small, I think the use of the smaller integration tolerance provided by "conservative" may not be warranted. It may not reduce your simulation time much, but may help.

4. Do you think your value of noisefmax = 10 GHz is truly supported by your circuit bandwidth? In other words, if the magnitude of your waveform harmonics do not extend to 10 GHz (large signal bandwidth), then the harmonic folding of the noise at those frequencies will be minimal. If you have not seen it, the application note at URL:

support.cadence.com/.../ArticleAttachmentPortal

provides a proposed means to establish the appropriate value of noisefmax for one's netlist on page 20.

5. If there is a significant settling time associated with your circuit, you can delay the start of the transient noise until after that settling time. The method to do this is provided on page 23 of the transient noise document at the aforementioned URL.

6. Does your circuit requirements include a noise specification that extends as low as you need the frequency noise components as low as 10 kHz? I assume this is setting the choice of your simulation stop time of 100 us. Hence, if it can be increased, the total simulation time can be reduced.

7. Finally, do you have access to Spectre X? I have not tried Spectre X with transient noise, but a colleague has found some simulation time reduction as compared to spectre ++aps (note, my personal recommendation is only +aps with conventional spectre - not ++aps where accuracy is deemed important).

I hope some of my thoughts provide you some added ideas or spur some insight!

Shawn
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Tobias Schirmer over 5 years ago in reply to ShawnLogan

Dear Shawn,

thank you so much for the very detailed answer and all your efforts!

Yes, I deleted the first part to shrink the number of lines a little bit. Unfortunately, I also deleted the important information few important information:

I'm working with Spectre Version 19.1.0.063 64bit and Cadence Virtuoso ICADV 12.3.

You recogniced that I made a quick 1us simulation because I needed to generate a new spectre.out file. The previous simulation files I didn't have anymore, but I can say that the simulation time scaled approximately linearly with the stop time.

I will try all the suggested changes and will send you my feedback as soon as possible. However, in the next week I will be out of office so I will not be able to give feedback in the next few days.

Thanks again for your help and best regards

Tobias
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ShawnLogan over 5 years ago in reply to Tobias Schirmer

Dear Tobius,

Thank you for the version information and your added comment about the simulation time roughly scaling with transient stop time. Both are very helpful!

The fact that the simulation time is scaling with simulation stop time is providing two clues in my experience:

1. There does not appear to be a convergence issue limiting the simulation time. Often this will lead to a nonlinear simulation time relationship with simulation stop time.

2. The simulation time is likely being established primarily by the maximum integration time step.

I will continue to think about your issue as you are away, and if you do have a chance when you return, let us know any results you may have or conclusions you have drawn.

Thank you Tobius!

Shawn
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Tobias Schirmer over 4 years ago in reply to ShawnLogan

Dear Shawn,

I'm sorry for the late feedback. I made some experiments and applied your suggestions to the simulation setup. I increased the integration time step by setting the accuracy to moderate. Now the step is at 50ps. Also as suggested, I delayed the start of the noise contribution to a simulation time, at which I'm actually interested in the noise of the circuit. All in all this helped to decrease the simulation time by approx. 70%.

Thank you very much for all your useful hints.

Best regards

Tobias
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ShawnLogan over 4 years ago in reply to Tobias Schirmer

Dear Tobius,

Tobias Schirmer said:
'm sorry for the late feedback.

Please, no apologies needed, you are busy too!

Tobias Schirmer said:
All in all this helped to decrease the simulation time by approx. 70%.

Excellent. I am happy to read that! Thank you for letting us know!

Shawn
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