This part is a kind of semiconductor called 25VF040B.

Function of this product has SST25VF040B.

Manufacturers : Silicon Storage Technology

Image and pinout :

Some of the text within the PDF file :

4 Mbit SPI Serial Flash SST25VF040B SST25VF040B4Mb Serial Peripheral Interface (SPI) flash memory Data Sheet FEATURES: • Single Voltage Read and Write Operations – 2.7-3.6V • Serial Interface Architecture – SPI Compatible: Mode 0 and Mode 3 • High Speed Clock Frequency – 50 MHz • Superior Reliability – Endurance: 100,000 Cycles (typical) – Greater than 100 years Data Retention • Low Power Consumption: – Active Read Current: 10 mA (typical) – Standby Current: 5 µA (typical) • Flexible Erase Capability – Uniform 4 KByte sectors – Uniform 32 KByte overlay blocks – Uniform 64 KByte overlay blocks • Fast Erase and Byte-Program: – Chip-Erase Time: 35 ms (typical) – Sector-/Block-Erase Time: 18 ms (typical) – Byte-Program Time: 7 µs [ ... ]

25VF040B PDF Datasheet Download