IBIS Semiconductor Buffer Modeling (.ibs)

@modelscript/ibis (languages/ibis) provides zero-regex parsing, non-linear driver I/V interpolation, dynamic VT ramp synthesis, package parasitics RLC lowering, and Modelica 3.x projection for ANSI/EIA-656 IBIS 3.2–7.1 input/output buffer information specifications.

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Supported Extensions & Standards

Extension	Format	Description
.ibs	IBIS Device Specification	Behavioral non-linear I/V tables, switching ramps, package parasitics, pin mappings

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Key Capabilities

1. Behavioral Non-Linear Driver & Receiver Formulation

• Replaces proprietary transistor-level SPICE netlists with behavioral table lookups that preserve intellectual property while accelerating high-speed digital signal integrity analysis:$$I_{\text{out}}(t)=k_u(t)\cdot I_{\text{pullup}}(V_{dd}-V_{\text{out}})+k_d(t)\cdot I_{\text{pulldown}}(V_{\text{out}})+I_{\text{gndclamp}}(V_{\text{out}})+I_{\text{pwrclamp}}(V_{\text{out}}-V_{dd})$$where $k_u(t)$ and $k_d(t)\in [0,1]$ are time-varying switching coefficients derived from the [Ramp] and [Rising/Falling Waveform] tables:$$\frac{dV}{dt}=\frac{V_{\text{swing}}}{t_r},\frac{dV}{dt}=\frac{V_{\text{swing}}}{t_f}$$
• Implements piecewise-linear monotonic cubic spline interpolation across Min/Typ/Max process, voltage, and temperature (PVT) operating corners.

2. Multi-Pin Package Parasitics

• Models chip-to-board interconnect parasitics via lumped RLC matrices and per-pin package values:$$V_{\text{pin}}-V_{\text{die}}=R_{\text{pkg}}{I}_{\text{pin}}+L_{\text{pkg}}\frac{d{I}_{\text{pin}}}{dt}$$$$I_{\text{die}}=I_{\text{pin}}-C_{\text{comp}}\frac{d{V}_{\text{die}}}{dt}-C_{\text{pkg}}\frac{d{V}_{\text{pin}}}{dt}$$where $C_{\text{comp}}$ is the silicon die capacitance.

3. Direct DAE Lowering

• Emits combined package RLC and non-linear buffer DAE equations into @modelscript/runtime's DAEBuilder linear memory arena.
• Enables co-simulation with multi-port S-parameter channel macromodels (@modelscript/touchstone) to assess eye diagrams, timing jitter, and simultaneous switching noise (SSN).

4. Bidirectional Modelica 3.x Projection

• Projects IBIS buffers into Modelica.Electrical.Analog non-linear controlled current sources and package RLC networks.

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Pre-Flight Diagnostics

The IBIS validator enforces monotonic I/V behavior and physical bounds:

9 rules2 warning7 error Run with msx ibis lint

Code	Rule	Severity	Message
M8303	non-monotonic-iv-curve	warning	IBIS model '<modelName>' contains non-monotonic slope in '<tableType>' table between <value>V and <value>V.
M8305	missing-pin-model-binding	error	Component pin '<pinName>' references undefined model '<modelName>'.
M8316	missing-component-pins	error	Component '<compName>' declaration has no defined pins in '[Pin]' section.
M8317	invalid-voltage-range	error	IBIS model '<modelName>' has invalid [Voltage Range]: min (<value>V) is greater than max (<value>V).
M8318	clamping-diode-divergence	warning	Model '<modelName>' clamp table '<clampType>' diverges to excessive current (<value>A).
M8319	missing-pullup-pulldown	error	Driver model '<modelName>' of type '<modelType>' is missing both I/V tables ([Pullup]/[Pulldown]) and [Ramp] slew rates.
M8320	negative-die-capacitance	error	IBIS model '<modelName>' specifies non-positive die capacitance C_comp '<val>'.
M8321	negative-package-parasitic	error	Component '<compName>' package parasitic '<param>' has non-positive value '<val>'.
M8322	no-models-defined	error	IBIS file contains no buffer [Model] definitions.

Generated from languages/ibis/src/errors.ts. All languages →

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CLI Usage

# Inspect pins, models, and package parasitics in an IBIS file
msx ibis inspect Ddr4Driver.ibs

# Run pre-flight linting and table monotonicity checks
msx ibis lint Ddr4Driver.ibs

# Evaluate driver dynamic currents and output resistance
msx ibis eval Ddr4Driver.ibs

# Lower buffer and package equations to ModelScript linear DAE arena
msx ibis to-dae Ddr4Driver.ibs

# Project into Modelica 3.x electrical analog component
msx ibis to-modelica Ddr4Driver.ibs -o Ddr4Buffer.mo