W25B40 Datasheet, PDF (4/36 Pages) Winbond – 4M-BIT SERIAL FLASH MEMORY WITH BOOT AND PARAMETER SECTORS

W25B40/W25B40A
1. GENERAL DESCRIPTION
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. (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 for Boot Code and
Parameter Storage
– Seven sectors of 64KB
– One sector each of 32KB, 16Kb and 8KB
– Two sectors of 4KB
– Bottom Boot organization (standard)
– Top Boot organization (special order)
• 4-pin SPI Serial Interface
– Clock, Chip Select, Data In, Data Out
– Easily interfaces to popular microcontrollers
– Compatible with SPI Modes 0 and 3
– Optional Hold function for SPI flexibility
• Low Power Consumption, Wide
Temperature Range
– Single 2.7 to 3.6V supply
– 5mA active current, <1µA Power-down
– -40° to +85°C operating range
• Fast and Flexible Serial Data Access
– Clock operation to 40MHz
– Byte-addressable Read and Program
– Auto-increment Read capability
– Manufacturer and Device ID
• Programming Features
– Page program up to 256 bytes 2mS
– Sector Erase 120mS to 650mS
– Chip erase 5.5 seconds
– 100,000 erase/write cycles
– Twenty-year data retention
• Software and Hardware Write
Protection
– Write-Protect all or portion of memory
– Enable/Disable protection with /WP pin
• SOIC Compatible Packaging
– Tiny 8-pin SOIC 150mil
• Ideal for systems with limited pins,
space, and power
– Controller-based serial code-download
– µC systems storing data, text or voice
– Battery-operated and portable product
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