4. Design methodologies

Specification

Figure 21 describes the general design flow of an integrated circuit. A circuit, from the simplest to the most complex, must be designed in accordance with its "specifications" if it is to be usable: this is the most critical phase, as it determines all the circuit's operating modes, which will be used in particular to establish the circuit's production test protocols at a later date. At this stage, it is essential to specify the technical constraints (electrical performance in terms of speed and power consumption, description of operation and identification of any specific functions —, in particular analog —, type of housing, etc.) and economic constraints (design and prototype manufacturing times, anticipated volumes of parts, human...