2. Substitution Conclusion for IS64LF25636A-7.5B3LA3-TR Conditionally feasible, with a critical need to evaluate timing and protocol compatibility risks. The substitute model is compatible with the original in fundamental parameters (density, organization, voltage, package). Two key differences exist: first, its performance metrics (7.5 ns access time, 117 MHz clock) are comparable to or slightly better than the original. Second, it is described as a standard "SDR" synchronous SRAM and does not explicitly support the "ZBT" feature inherent to the original part. ZBT is a protocol designed to eliminate bus latency during read/write turnarounds. In applications with frequent read/write switching, the substitute may lead to reduced bus efficiency or necessitate controller timing adjustments. The feasibility of this substitution depends heavily on whether the original system design strictly relies on the ZBT protocol to achieve maximum bandwidth. It can be used as a replacement in applications that are not bandwidth-critical or do not involve frequent turnarounds; otherwise, there is a potential risk of not meeting performance targets.