W25B40/W25B40A
4M-BIT SERIAL FLASH MEMORY
WITH BOOT AND PARAMETER SECTORS
Formally NexFlash NX25B40
The Winbond W25B40 / W25B40A is fully compatible with the previous NexFlash NX25B40 Serial
Flash memory.
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Publication Release Date: January 6, 2006
Revision M
W25B40/W25B40A
Table of Contents-
1.
2.
3.
4.
GENERAL DESCRIPTION ......................................................................................................... 4
FEATURES ................................................................................................................................. 4
PIN CONFIGURATION ............................................................................................................... 5
PIN DESCRIPTION..................................................................................................................... 5
4.1
4.2
4.3
4.4
4.5
4.6
4.7
5.
6.
7.
Package Types ............................................................................................................... 5
Chip Select (/CS) ............................................................................................................ 5
Serial Data Output (DO) ................................................................................................. 6
Write Protect (/WP)......................................................................................................... 6
Hold (/HOLD) .................................................................................................................. 6
Serial Clock (CLK) .......................................................................................................... 6
Serial Data Input (DI) ...................................................................................................... 6
BLOCK DIAGRAM (BOTTOM BOOT) ........................................................................................ 7
BLOCK DIAGRAM (TOP BOOT-SPECIAL ORDER) ................................................................. 8
FUNCTIONAL DESCRIPTION ................................................................................................... 9
7.1
SPI OPERATIONS ......................................................................................................... 9
7.1.1
7.1.2
SPI Modes ........................................................................................................................9
Hold Function ...................................................................................................................9
Write Protect Features......................................................................................................9
Write Protection using Power-down instruction...............................................................10
7.2
WRITE PROTECTION.................................................................................................... 9
7.2.1
7.2.2
8.
CONTROL AND STATUS REGISTERS................................................................................... 10
8.1
STATUS REGISTER .................................................................................................... 10
8.1.1
8.1.2
8.1.3
8.1.4
8.1.5
8.1.6
8.1.7
BUSY..............................................................................................................................10
Write Enable Latch (WEL) ..............................................................................................10
Block Protect Bits (BP2, BP1, BP0)................................................................................11
Reserved Bits .................................................................................................................11
Status Register Protect (SRP) ........................................................................................11
Write Protection Operation - Bottom Boot Sector Organization ......................................12
Write Protection Operation - Top Boot Sector Organization (Special Order) ..................12
Manufacturer and Device Identification...........................................................................13
Instruction Set
(1)
.............................................................................................................13
Write Disable (04h).........................................................................................................14
Write Enable (06h)..........................................................................................................14
Read Status Register (05h) ............................................................................................15
Write Status Register (01h) ............................................................................................16
8.2
INSTRUCTIONS........................................................................................................... 12
8.2.1
8.2.2
8.2.3
8.2.4
8.2.5
8.2.6
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W25B40/W25B40A
8.2.7
8.2.8
8.2.9
8.2.10
8.2.11
8.2.12
8.2.13
8.2.14
Read Data (03h) .............................................................................................................17
Fast Read (0Bh) .............................................................................................................18
Page Program (02h) .......................................................................................................19
Sector Erase (D8h).......................................................................................................20
Chip Erase (C7h)..........................................................................................................21
Power-down (B9h) ........................................................................................................22
Release Power-down / Device ID (ABh) .......................................................................23
Read Manufacturer / Device ID (90h) ...........................................................................25
9.
ELECTRICAL CHARACTERISTICS......................................................................................... 26
9.1
Absolute Maximum Ratings (1) .................................................................................... 26
9.2
9.3
9.4
9.5
9.6
9.7
9.8
9.9
9.10
Operating Ranges......................................................................................................... 26
Power-up Timing and Write Inhibit Threshold .............................................................. 27
DC Electrical Characteristics (Preliminary) (1) ............................................................. 28
AC Measurement Conditions........................................................................................ 29
AC Electrical Characteristics (Preliminary)................................................................... 30
AC Electrical Characteristics (Preliminary) cont’d ........................................................ 31
Serial Output Timing ..................................................................................................... 32
Input Timing .................................................................................................................. 32
Hold Timing................................................................................................................... 32
8-Pin SOIC 150-mil (Package Code SN)...................................................................... 33
10.
11.
12.
PACKAGE SPECIFICATION .................................................................................................... 33
10.1
ORDERING INFORMATION .................................................................................................... 34
REVISION HISTORY ................................................................................................................ 35
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Publication Release Date: January 6, 2006
Revision M
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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W25B40/W25B40A
3. PIN CONFIGURATION
Figure 1. W25B40 / W25B40A Pin Assignments, 8-pin SOIC (Package Code SN)
4. PIN DESCRIPTION
PIN NO.
PIN NAME
I/O
FUNCTION
1
2
3
4
5
6
7
8
/CS
DO
/WP
GND
DI
CLK
/HOLD
VCC
I
O
I
I
I
I
Chip Select Input
Data Output
Write Protect Input
Ground
Data Input
Serial Clock Input
Hold Input
Power Supply
4.1
Package Types
The standard package for the W25B40 / W25B40A is an 8-pin plastic SOIC with 150-mil body
(Winbond package code SN) (NexFlash package code N). The pinout for the package is shown in
Figure 1. Package diagram and dimensions are illustrated at the end of this data sheet.
4.2
Chip Select (/CS)
The SPI Chip Select (/CS) pin enables and disables device operation. When /CS is high the device is
deselected and the Serial Data Output (DO) pin is at high impedance. When deselected, the devices
power consumption will be at standby levels unless an internal erase, program or status register cycle
is in progress. When /CS is brought low the device will be selected, power consumption will increase
to active levels and instructions can be written to and data read from the device. After power-up, /CS
must transition from high to low before a new instruction will be accepted. The /CS input must track
the VCC supply level at power-up (see “Write Protection” and figure 18). If needed a pull-up resister
on /CS can be used to accomplish this.
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Publication Release Date: January 6, 2006
Revision M
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