To enable design reusability and system integration, we apply the communication based design (CBD) methodology to analog design, i.e., CBD-A. In CBD, formal specifications are used and communication adapters are introduced to deal with the mismatch between communicating blocks without modifying the incompatible blocks. Such adapters enable the interaction between the incompatible blocks. In CBD-A, similar adapters are inserted between analog blocks. To provide suitable adapters, a formal description of the analog interface is required, such as DC level, dynamic range, driving/loading capabilities, biasing requirements, and so on. On the other hand, since the analog block acting as an adapter introduces some non-ideal effects which will cause degradation on the signal (e.g., SNR degradation), we need to know the specifications of the adaptation block in terms of inserted noise, distortion, CMRR, etc.
Currently, we are exploring CBD-A based on an available hardware platform, field programmable analog array (FPAA). Its unique feature is to implement analog functions in reconfigurable architecture. So, it gives us the analog equivalent of FPGA. The FPAA is based on CMOS-based fully differential switched-capacitor technology with an analog switch fabric.
To implement analog interface adapters with FPAA, some dedicated simulation strategies based on FPAA behavioral models are developed to ensure fast and accurate estimations of the non-ideal effects introduced by specific FPAA configurations. Another part of this research is to formalize the analog interface specification from the electrical point of view and also formalize the signal degradation. We plan to develop a synthesis mechanism to map analog system descriptions and interface specifications onto an FPAA platform.