Statistical timing analysis is an area of growing importance in nanometer te- nologiesa as the uncertainties associated with process and environmental var- tions increasea and this chapter has captured some of the major efforts in this area. This remains a very active field of researcha and there is likely to be a great deal of new research to be found in conferences and journals after this book is published. In addition to the statistical analysis of combinational circuitsa a good deal of work has been carried out in analyzing the effect of variations on clock skew. Although we will not treat this subject in this booka the reader is referred to [LNPS00a HN01a JH01a ABZ03a] for details. 7 TIMING ANALYSIS FOR SEQUENTIAL CIRCUITS 7.1 INTRODUCTION A general sequential circuit is a network of computational nodes (gates) and memory elements (registers). The computational nodes may be conceptualized as being clustered together in an acyclic network of gates that forms a c- binational logic circuit. A cyclic path in the direction of signal propagation 1 is permitted in the sequential circuit only if it contains at least one register . In general, it is possible to represent any sequential circuit in terms of the schematic shown in Figure 7.1, which has I inputs, O outputs and M registers. The registers outputs feed into the combinational logic which, in turn, feeds the register inputs. Thus, the combinational logic has I + M inputs and O + M outputs.2. A. QUICK. OVERVIEW. OF. CIRCUIT. SIMULATION. 2.1 INTRODUCTION Circuit simulation provides an methodical procedure for writing the equations that describe a circuita and utilizes numerical techniques to solve them to an accuracy anbsp;...
|Publisher||:||Springer Science & Business Media - 2007-05-08|