256 Mbit NOR Flash with Quad-SPI — what it delivers for the memory bus
The Infineon S25FL256SAGMFIG00 is a 256 Mbit (32M x 8) NOR Flash memory from the FL-S series, built for code-shadowing, data logging, and firmware-over-air staging in embedded systems. It communicates over a standard SPI bus with Quad I/O support, pushing the read clock to 133 MHz — which translates to roughly 66 MB/s theoretical throughput in quad-output mode, enough to feed a Cortex-M or entry-level application processor without stalling the instruction bus.
Quad I/O at 133 MHz — why the interface speed matters
Quad-SPI is the main event here. A standard SPI bus at 133 MHz delivers 133 Mbps; with four data lines active in quad-output mode, the same clock yields 532 Mbps raw. For a 256 Mbit part that means a full-chip read in under half a second — relevant for fast boot times and OTA update windows. The FL-S series also supports continuous read (XIP) so the MCU can execute code directly from the Flash without copying to RAM first, as long as the memory controller handles the quad-address wraparound.
Package and footprint — 16-SOIC wide body
Housed in a 16-SOIC wide-body package (0.295-inch body width, 7.50 mm), the part is a surface-mount device that reflows on standard lead-free profiles. The 16-SOIC footprint is common across the FL-S family, so a board laid out for one density option can often take a drop-in replacement at a different capacity — useful for mid-life capacity upgrades without a PCB spin.