The Rapid Prototyping of Application Specific Signal Processors (RASSP) program has as its goal the dramatic improvement of the process by which signal processors are specified, designed, documented, manufactured, and supported. A key part of the RASSP process is the method of architecture selection. An architecture overview is presented, together with a discussion of architecture classification, architecture evaluation factors, and signal processing flow. Two important architecture support aspects are briefly discussed: open systems architecture and integrated diagnostics. Recommendations for preferred approaches and rules of thumb for architecture selection are given. Finally, the RASSP architecture selection process is outlined, including a discussion of a standard hardware/software module interface.