512 Kbit SPI flash in an 8-SOIC — what you're looking at
The Microchip SST25VF512A-33-4C-SAE is a 512 Kbit serial NOR flash memory that talks over an SPI bus at up to 33 MHz. The part is from the SST25 family, uses standard SPI commands, and is rated for commercial temperatures from 0°C to 70°C — think office gear, appliance controllers, or any indoor PCB where you need a small firmware/parameter store without the overhead of a parallel flash.
The SPI interface runs at 33 MHz. Page program time is 20 µs per word or page.
The ROHS3 compliance is also confirmed, so it's ready for lead-free assembly lines.