Patent ID: 8417505

Claim:
A method for simulating an analog and mixed-signal circuit design comprising an analog circuit segment and a transmission gate network of a digital circuit segment, the method comprising: inserting a bi-directional connect module at a connection point between the analog circuit segment and a terminal of a transmission gate network, wherein the bi-directional connect module comprises an analog port connected to the analog circuit segment, and a digital port connected to the transmission gate network; and when simulating the analog and mixed-signal circuit, evaluating the bi-directional connect module and the transmission gate network such that the analog circuit segment contributes an analog driving force to the transmission gate network as a digital driver, and the transmission gate network contributes a digital driving force to the analog circuit segment as an analog driver, wherein the transmission gate network comprises a first set of N terminals Tn having a first subset of M terminals Tm connected one-to-one to a second set of M bi-directional connect modules Bm, where M≦N, and wherein evaluating the bi-directional connect module and the transmission gate network comprises: adding a transmission gate TGm to the transmission gate network for each terminal Tm of the first set, wherein each TGm is inserted between a terminal Tm of the first subset and a bi-directional connect module Bm of the second set; segregating the transmission gate network into a driver network and a receiver network such that: the driver network comprises driver transmission gates TGm_d of TGm, the receiver network comprises receiver transmission gates TGm_r of TGm, each driver transmission gate TGm_d comprises an input terminal TGm_d_in connected to an output terminal Tm_out of Tm and an output terminal TGm_d_out connected to a digital input port of a bi-directional connect module Bm, and each receiver transmission gate TGm_r comprises an input terminal TGm_r_in connected to a digital output port of a bi-directional connect module Bm and an output terminal TGm_r_out connected to an input terminal Tm_in of Tm; evaluating each Bm, for m=1 to M, such that it does not perform digital resolution or analog resolution; evaluating each TGm_d_out, for m=1 to M, as a function of Tx_in for x=1 to N, and TGy_r_in for y=1 to M, while enforcing high impedance Z on TGm_r_in; and evaluating each Tm_out, for m=1 to M, as a function of Tx_in for x=1 to N, and TGy_r_in for y=1 to M.