133 MHz Quad SPI — throughput for execute-in-place
The S25FL128SAGMFIG11: That clock rate translates to a sustained read throughput that keeps a Cortex-M or RISC-V core fed with instructions in execute-in-place (XIP) mode without needing a separate RAM shadow — a common design pattern in industrial controllers and IoT gateways where firmware is large enough to justify a dedicated Flash device but not a DRAM.
Supply and temperature — where it runs
If your design lives in a -40°C cold-start or a 70°C+ summer cabinet, this part's temperature grade is a direct match.
Package and footprint — 16-SOIC wide-body
Housed in a 16-SOIC package with a 7.50 mm body width — the wide-body SOIC footprint that is standard for serial NOR Flash in this density tier.