
Memory, Cell Library & IBIS Model, and Lowering Vdd Analysis

What is the RC reduction algorithn used in SpiceCut/ CharFloMemory!?
Answer:
AWE (Asymptotic Waveform Evaluation) method is used in SpiceCut to execute RC reduction.
Two reference papers are listed below

Chiprou and Nakhla, Asymptotic Waveform Evaluation And Moment Matching for Interconnect Analysis (Kluwer Academic Publishers, 1994).

C. L. Ratzlaff and L.T. Pillage, "RICE: Rapid Interconnect Circuit Evaluation Using AWE," IEEE Trans. On ComputerAided Design, Vol. CAD13 No 6, pp. 763776,1994.
AWE can be used in both RC delay calculation and RC reduction. For delay calculation, AWE is a qth (e.g. 2 or 3) order extension of Elmore delay (1st order) for RC circuits. When moving from time domain to frequency domain, the q dominentpoles approximation can be applied through moment matching. This method just need solve a small qth moment matrix instead of a large RC matrix in time domain. After the poles and residues are obtained, the delay can be calculated. For RC reduction, similar algorithms are applied, but the error controlled by both the tolerance specification and maximum frequency.
What are the CCS models supported by CharFloMemory!?
Answer:
Based on channelconnected blocks (CCB) partitioned by SpiceCut, CharFloMemory! can characterize
 CCS Timing model,
 CCS Power model, and
 CCS Noise model
Please see the white paper
Characterizing CCS Timing Model of Memory IP by Using CharFloMemory!



