Design Platform for Electrical and Physical Co-design of Analog Circuits

摘要

Although there exists a large amount of work in the field of automated design of analog integratedrncircuits [1], most of the work focuses on either the electrical design or on the physical design of such circuits. Theserntwo steps remain as two distinct processes. It is also well understood that that physical considerations (e.g.,rnmatching, proximity effects [2]), especially for 32nm and below, can have an important effect in the performance ofrnanalog circuits.rnIn this paper we present Titan, a platform that allows the simultaneous electrical and physical co-design of customrnmixed-signal circuits. The design process in Titan consists in first capturing the electrical and physical designrnconstraints into an analytical form, then using numerical optimization techniques to produce a design that meets thernrequired specifications and finally running verification on the full design over the critical design scenarios. Thernadvantages of such a design environment include:rn1. Easy, semi-automated way of entering constraints – as opposed to cumbersome schematic & text entryrn2. Shorter design cycles– rather than back-annotating designs with post extracted layout information, designs arerneffectively pre-annotated with good estimates of physical effects (layout parasitic, proximity effects, …)rn3. Higher quality designs by allowing the co-optimization of both electrical and physical constraints. Physicalrntradeoffs (e.g., area, length) can be traded-off with top level specifications (e.g., power, jitter)rn4. Effective communication with mask engineers by providing a visual view and a text form of the circuitrndesigners’ layout intent.rn5. Early estimation of die size requirements and the capability of performing initial system level tradeoffs.