Expand description
The non-ideality model — sourced physics, seeded instances, and the instance evaluator.
Every constant here is SOURCED or DERIVED-with-shown-arithmetic (see
benchmarks/silicon/analog/sourced-constants.md for the full dossier with URLs and exact quotes) or
loudly MODELED (a design parameter of our fabric awaiting the characterization ladder:
schematic SPICE → PVT → Monte-Carlo mismatch → extraction → silicon). An invented physical
constant is none of these and ships never; analog_provenance_lock pins both the values
and their source strings.
An InstanceSample is one manufactured die: per-leg gain errors (unit-element/programming
accuracy plus the Pelgrom DISTANCE term over the placed operand separation) and per-tile
output offsets and a frozen noise realization — drawn from fixed-seed SplitMix64 + Box–Muller,
so every Monte-Carlo battery is deterministic forever.
Structs§
- Instance
Sample - One manufactured die: per-cell per-leg fractional gain errors, per-cell output offsets (volts), and a frozen per-cell noise realization (volts).
- NonIdeality
Model - The characterized non-ideality figures a physical target carries.
Enums§
- Separation
- Physical separation of a tile from its operand — the Pelgrom law’s input. Same-tier separation is a distance (the gradient applies); separately manufactured tiers are a CATEGORY, not a distance.
Constants§
- KSIGMA
- The k·σ envelope every budget term and frozen draw uses. At k = 6 a fixed-seed battery is deterministically green forever (p(>6σ) ≈ 2e-9 per draw, evaluated once at authoring time).
Functions§
- eval_
analog_ instance - Evaluate one die: the volt-domain converter path over the QUANTIZED netlist with the instance’s gain errors, offsets, and frozen noise applied per tile.
- eval_
analog_ instance_ chopped - Evaluate one die CHOPPED: two frames — normal and polarity-swapped (each frozen offset
enters negated) — with FRESH noise per frame (drawn from
frame_seed), averaged by the digital side. The frozen offsets cancel EXACTLY; what survives is a deterministic intra-pair residual draw (the model’schop_residual_vclass) and √2-averaged noise. - leg_
sigma - The per-leg 1σ gain-error class over a 2D placement — the shared law at
SameTier. - sample_
instance - Draw one die. Deterministic in
seed. - separation_
sigma - THE shared separation law every budget composes with: programming accuracy plus the
distance gradient in-tier; programming accuracy plus the flat categorical ceiling across
tiers. 2D
leg_sigmaand the 3D stacked budget are both thin wrappers over this. - sky130_
nonideal - The SKY130-class model.