SIMULATING DIGITAL CIRCUITS NUMERICALLY - A CHARGE-ORIENTED ROW APPROACH

A ROW type approach is considered for integral form DAEs arising in ch arge-oriented nodal analysis of digital networks. These network equati ons define very special index-2 systems that can be solved by Rosenbro ck-Wanner (ROW) methods suitable for semi-explicit index-1 systems wit hout order reduction. To obtain charge conservation, the charge variab les are projected on the linear charge constraint. In contrast to the semi-explicit index-1 case, all order conditions for the algebraic var iables up to order p have to be fulfilled for a method of order p. CHO RAL, an embedded charge-oriented method of order (2)3, is introduced a nd compared with DASSL and RODAS for two industrial applications, the NAND gate and the two-bit adding unit.