Discrete time analog polynomial type CNN with digital state

In this paper a CNN with digital state and analog multiplication is presented. Better control of delays of different order feedback terms can be achieved with the mixed mode approach. Also, errors generated at the beginning of transients can be reduced and storage of the initial states is straightforward in the digital domain. Euler-Cauchy, Heun´s and Runge-Kutta integration methods are compared in terms of convergence time and aspects of cell level implementation. Heun´s method is found to be the best compromise in hardware realizations where network dynamics are critical. Also, a current squarer and four quadrant multiplier with low quiescent current are presented