Part Number : M25P40
Function : 4 Mbit, low voltage, serial Flash memory with 50 MHz SPI bus interface
Package : 8 Pin Type
Maker : Micron, STM
Pinouts : 
Description :
The M25P40 is a 4 Mbit (512 K × 8) Serial Flash memory, with advanced write protection mechanisms, accessed by a high speed SPI-compatible bus.
The memory can be programmed 1 to 256 bytes at a time, using the Page Program instruction.
The memory is organized as 8 sectors, each containing 256 pages. Each page is 256 bytes wide.
Thus, the whole memory can be viewed as consisting of 2048 pages, or 524,288 bytes.
The whole memory can be erased using the Bulk Erase instruction, or a sector at a time, using the Sector Erase instruction.
Features :
1. 512Kbit to 32Mbit of Flash Memory
2. Page Program (up to 256 Bytes) in 1.4ms (typical)
3. Sector Erase (256 Kbit or 512Kbit)
4. Bulk Erase (512Kbit to 32Mbit)
5. 2.7 to 3.6V Single Supply Voltage
6. SPI Bus Compatible Serial Interface
7. 40MHz to 50MHz Clock Rate (maximum)
Datasheet PDF Download : 
Others datasheet of same file :
25P40, M25P40–VMN6TP, M25P40–VMN6TP/X,
M25P40–VMP6TP, M25P40–VMP6TP/X
