512 Mbit NOR Flash for code and data storage
At 133 MHz with Quad I/O, the effective read bandwidth is about 66 MB/s in fast-read quad mode. That is enough to shadow a 512 Mbit firmware image into RAM in under a second, or stream sensor logs without stalling the host controller. The SPI interface keeps the pin count to six signals (CS, SCK, IO0-IO3), which simplifies PCB routing compared to a parallel NOR bus.
The 16-SOIC wide-body package (0.295-inch body width) is hand-solderable and inspectable, which helps during prototype rework or field repair.