Modifica questa pagina Puntano qui Rename Page Fold/unfold all ====== Simulation references ====== [ __[[vlsi:home|Home]]__ ] [ __[[vlsi:workbook|VLSI Design WorkBook]]__ ] [ __[[vlsi:workbook:analog:main#contents|Back to index]]__ ] == Contents == * [[vlsi:analog_simref#introduction|Introduction]] * [[vlsi:analog_simref#reference_documentation|Reference documentation]] * [[vlsi:analog_simref#dc_operating_points|DC operating points]] * [[vlsi:analog_simref#power_consumption_evaluation|Power consumption evaluation]] * [[vlsi:analog_simref#ADE_simulation_options|ADE simulation options]] * [[vlsi:analog_simref#node_impedance_simulation|Node impedance simulation]] * [[vlsi:analog_simref#pwl_voltage_and_current_sources|PWL voltage and current sources]] * [[vlsi:analog_simref#noise_analyses|Noise analyses]] **Keywords:** ===== Introduction ===== In this page we give a detailed description of a few **common simulation tasks** (e.g. //power consumption evaluation// in Cadence) which can be encountered during the analog design activity. ===== Reference documentation ===== Spectre ssimulator official documentation! Si impara praticamente tutto! Attenzione pero' che e' sotto **MMSIM** (Multi-Mode Simulation) package! //Spectre User Guide// and //Spectre Reference Guide// ''/usr/cadence/MMSIM_10.11/doc/spectreuser/spectreuser.pdf'' ''/usr/cadence/MMSIM_10.11/doc/spectreref/spectreref.pdf'' ===== DC operating points ===== MOS transistor parameters evaluated from the transistor model, typically some version of the **BSIM4** model. **ADE L => Results => Print => DC Operating Points** Quali DOP vengono elencati dipende poi dal modello! I DC op. poiints piu' importanti sono: ^ Parameter ^ Description ^ |''<sub>betaeff </sub>''| | |''<sub>gds </sub>''| | |''<sub>gm </sub>''| | |''<sub>id </sub>''| | |''<sub>ids </sub>''| | |''<sub>region </sub>''| | |''<sub>ron </sub>''| | |''<sub>vds </sub>''| | |''<sub>vdsat </sub>''| | |''<sub>vgs </sub>''| | |''<sub>vth </sub>''| | \\ ''betaeff''\\ \\ ''gmoverid''\\ etc. ===== Analyses overview ===== breve rassegna di cosa vuol dire simualre DC, TRAN, AC etc. ^ **Calculator** ^ **Description** ^ **OCEAN syntax example ** ^ | ''<sub> vt </sub>''| wire transient voltage | ''<sub>VT("/out") </sub>''| | ''<sub> it </sub>''| node transient current | ''<sub>IT("/M1/D") </sub>''| | ''<sub> vf </sub>''| wire AC sweep voltage | ''<sub>VF("/Vin") </sub>''| | ''<sub> if </sub>''| node AC sweep current | ''<sub>IF("/C0/MINUS") </sub>''| | ''<sub> vdc </sub>''| wire DC voltage | ''<sub>VDC("/vdd_disc") </sub>''| | ''<sub> idc </sub>''| node DC current | ''<sub>IDC("/V0/PLUS") </sub>''| | ''<sub> vs </sub>''| wire DC sweep voltage | ''<sub>VS("/net012") </sub>''| | ''<sub> is </sub>''| node DC sweep current | ''<sub>IS("/R1/PLUS") </sub>''| | ''<sub> op </sub>''| instance DC operating point | ''<sub>OP("M0","gm") </sub>''| | ''<sub> opt </sub>''| instance transient DC operating point | ''<sub>OPT("M0","vth") </sub>''| | ''<sub> var </sub>''| design variable | ''<sub>VAR("Ibias") </sub>''| | ''<sub> mp </sub>''| instance model parameter | ''<sub>MP("M0","vtho") </sub>''| ===== Power consumption evaluation ===== How to evaluate the power consumption. A detailed Wiki page about this topic has been created, see __[[vlsi:analog_power_sim|here]]__. ===== ADE simulation options ===== Importante! soprtattutto a livello di **numerical evaluation**, serve sapere che esistono dei **checks** su gmin, etc. **ADE L => Simulation => Options => Analog...** {{:vlsi:spectre_simulator_options_main.png}} {{:vlsi:spectre_simulator_options_check.png}} ===== Node impedance simulation ===== How to evaluate the **total impedance** at a node. A detailed Wiki page about this topic has been created, see __[[vlsi:analog_impedance_sim|here]]__. ===== PWL voltage and current sources ===== piecewise linear (PWL) Vpwl (piece-wise linear) to be used in **transient simulations**. Values can be also specified into a plain text file and then using a **Vpwlf** voltage source, which takes file values and convert them to a standard **Vpwl** source. **analogLib => Sources => Independent => Vpwlf** The syntax is a column of time values and a column of voltage or current values, <code> t0 vo t1 v1 t2 v2 ... ... </code> Specify the **full path to the file** or copy it in the same directory of the netlist <code> cd ~/scratch/<tech_dir>/data mkdir vpwlf </code> Notare che posso anche passare il nome del file ad ADE come variabile, usare <code> pPar("filename") </code> nel CDF parameter dell'istanza. [[http://www.cadence.com/Community/forums/t/23078.aspx]] ===== Noise analyses ===== Both standard AC noise analysis and transient noise analysis. Click [[vlsi:workbook:analog:simref:noise|here]]. ====== ====== \\ ---- Last update: [[pacher@NOSPAMto.infn.it|Luca Pacher]] - Apr 23, 2013 ~~NOTOC~~