U. Choudhury et A. Sangiovannivincentelli, CONSTRAINT-BASED CHANNEL ROUTING FOR ANALOG AND MIXED ANALOG-DIGITAL CIRCUITS, IEEE transactions on computer-aided design of integrated circuits and systems, 12(4), 1993, pp. 497-510
The goal of routing in analog and mixed analog/digital circuits is not
simply to achieve the required connections in minimum area, but also
to satisfy a set of constraints on parasitics which affect circuit per
formance. For many mixed analog/digital circuits designed today there
is a need to develop channel routing algorithms for channels containin
g analog nets. In this paper, algorithms for mapping a set of bounding
constraints on critical coupling capacitances into constraints in the
vertical-constraint graph of the channel are presented. When the chan
nel height is then minimized, the minimization is automatically subjec
ted to the coupling constraints. For differential circuits, it may be
necessary to match specific pairs of interconnect parasitics. A techni
que is presented which tries to match the parasitics for pairs of nets
having intersecting horizontal spans in the channel. The concepts pre
sented in this paper can be used for high-performance digital VLSI als
o.