Winbond Electronics Corporation W25B40
The W25B40 / W25B40A is a 4Mb (512KB) Serial Flash Memory with erasable sectors that allows for boot code and parameter storage. The W25B40 / W25B40A is packaged in an 8-pin SOIC 150-mil and is compatible with the standard W25P40 specification with the following exceptions. • The W25B40 / W25B40A has twelve sectors instead of eight including: seven sectors of 64KB, one sector of 32KB, one sector of 16KB, one sector of 8KB and two sectors of 4KB.| Part No. | W25B40 |
|---|---|
| Datasheet | W25B40 Download |
| Manufacturer |  Winbond Electronics Corporation |
| Description | 4M-BIT SERIAL FLASH MEMORY |
| Buy | Stock & Price |
GENERAL DESCRIPTION
(see figure 2a and 2b)● The W25B40 / W25B40A status register write protect bits (BP2, BP1, and BP0) can protect the boot and parameter sectors. Unlike other Serial Flash devices, that only protect large portions of the memory and typically from the top address down, the W25B40 / W25B40A can protect boot code stored in the small sectors for either bottom or top boot configurations. This feature makes the process of field updates more robust and reliable. (See Write Protection Operation table)
● The W25B40 / W25B40A Bottom Boot Device ID is 32h instead of 12h as with the 25P40. Optional Top Boot is 42h. The Winbond W25B40 / W25B40A is fully compatible with the previous NexFlash NX25B40 Serial Flash memory. 2.
FEATURES
● W25B40 / W25B40A 4M-bit Serial Flash – 4M-bit /512K-byte (524,288) – 256-bytes per programmable page● Compatible with W25P40 with special features – Small Boot and Parameter Sectors – Write protection of Boot/Parameter area
● Variable Sector Sizes fo...
