1. Substitution Analysis for 71V65603S100BQG From the perspectives of pinout, package, voltage, and logic functionality, the 71V65603S100BQG is a fully compatible drop-in replacement for the original part. This is confirmed by its identical package (165-CABGA), voltage range (3.3V), memory density and organization (256K x 36), and interface type (parallel ZBT). The key performance deviations are its maximum operating clock frequency of 100 MHz (versus 133 MHz for the original) and an access time of 5 ns (versus 4.2 ns). Substituting with this part will result in an approximate 25% reduction in peak system data bandwidth and slower memory response. If the original system has sufficient design margin or operates below 100 MHz, the substitution is viable. However, if the system was running near the 133 MHz limit, direct replacement may cause timing violations, leading to system instability or failure. 2. Substitution Analysis for 71V65603S100BQGI The 71V65603S100BQGI is identical to the 71V65603S100BQG in all electrical parameters and performance specifications, and therefore presents the same performance degradation concerns related to the lower clock frequency and access time. The sole distinction is the suffix "I," which typically indicates support for a wider or specific industrial-grade temperature range. If the original application has specific temperature requirements (e.g., needing to meet industrial standards), the 71V65603S100BQGI may be the more suitable replacement. For standard commercial temperature applications, its substitution feasibility is identical to that of the 71V65603S100BQG. In both cases, the performance derating is the primary consideration and must be thoroughly validated in the derated system.