NexFlash Technologies, Inc.
1
PRELIMINARY
NXSF016F-1201
12/12/01
This document contains PRELIMINARY INFORMATION. NexFlash reserves the right to make changes to its product at any time without notice in order to improve design and supply the best possible
product. We assume no responsibility for any errors which may appear in this publication.
Copyright 2001, NexFlash Technologies, Inc.
PRELIMINARY
DECEMBER 2001
NX25F011B, NX25F021B, NX25F041B
1M-BIT, 2M-BIT, AND 4M-BIT
SERIAL FLASH MEMORIES WITH 4-PIN SPI INTERFACE
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NexFlash Technologies, Inc.
PRELIMINARY
NXSF016F-1201
12/12/01
NX25F011B
NX25F021B
NX25F041B
Table of Contents
1M-BIT, 2M-BIT, AND 4M-BIT ......................................................................................................................................... 1
SERIAL FLASH MEMORIES WITH 4-PIN SPI INTERFACE .......................................................................................... 1
FEATURES ..................................................................................................................................................................... 4
DESCRIPTION ............................................................................................................................................................... 4
FUNCTIONAL OVERVIEW ............................................................................................................................................. 5
Pin Descriptions ....................................................................................................................................................... 5
Package ............................................................................................................................................................... 5
Serial Data Input (SI) ............................................................................................................................................ 6
Serial Data Output (SO) ....................................................................................................................................... 6
Serial Clock (SCK) ............................................................................................................................................... 6
Chip Select (CS) .................................................................................................................................................. 6
Write Protect (WP) ............................................................................................................................................... 6
Hold or Ready/Busy (HOLD or R/B) ...................................................................................................................... 6
Power Supply Pins (Vcc and Gnd) ........................................................................................................................ 6
Serial Flash Memory Array ....................................................................................................................................... 7
Serial SRAM ............................................................................................................................................................. 8
Using the SRAM Independent of Flash Memory ................................................................................................... 9
Write Protection ........................................................................................................................................................ 9
Configuration Register .............................................................................................................................................. 9
Write Protect Range and Direction, WR[3:0], WD ................................................................................................ 10
Read Clock Edge, RCE ...................................................................................................................................... 10
Table 2A. Write Protect Range Sector Selection (Hex) ........................................................................................ 11
Table 2B. Write Protect Range Sector Selection (Hex) ........................................................................................ 11
Table 2C. Write Protect Range Sector Selection (Hex) ........................................................................................ 11
HOLD-R/B, HR[1:0] ............................................................................................................................................ 11
Status Register Bit Descriptions ............................................................................................................................. 12
Compare Not Equal, CNE ................................................................................................................................... 12
Power Detect, PD ............................................................................................................................................... 12
Write Enable/Disable, WE ................................................................................................................................... 12
Command Set ........................................................................................................................................................ 13
Command Set for the NX25F011B, NX25F021B and NX25F041B Serial Flash Memory ..................................... 15
SERIAL FLASH SECTOR COMMANDS ....................................................................................................................... 16
Read From Sector (52H) ......................................................................................................................................... 16
Read From Sector with Auto Increment (50H) ......................................................................................................... 16
Read From Sector Low Frequency (51H) and .......................................................................................................... 16
Read From Sector Low Frequency with Auto Increment (5BH) ................................................................................ 16
Write Enable (06H) .................................................................................................................................................. 16
Write Disable (04H) ................................................................................................................................................. 16
Write to Sector Through SRAM (F3H) ..................................................................................................................... 18
SERIAL SRAM COMMANDS ....................................................................................................................................... 19
Write to SRAM Command (72H) ............................................................................................................................. 19
Read from SRAM (71H) .......................................................................................................................................... 19
Transfer All of SRAM to Sector (F3H) ..................................................................................................................... 20
Transfer All of Sector to SRAM (53H) ..................................................................................................................... 20
Compare Sector to SRAM (8DH) ............................................................................................................................ 21
CONFIGURATION AND STATUS COMMANDS ............................................................................................................ 21
Read Configuration Register (8CH) ......................................................................................................................... 21
Write Non-Volatile Configuration
Register (8AH) ........................................................................................................................................................ 22
NX25F011B
NX25F021B
NX25F041B
NexFlash Technologies, Inc.
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PRELIMINARY
NXSF016F-1201
12/12/01
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Table of Contents
(cont'd)
Read Status Register (84H) .................................................................................................................................... 22
Clear Compare Status (89H) ................................................................................................................................... 23
Set Power Detection Bit (03H) ................................................................................................................................ 23
Reset Power Detection Bit (09H) ............................................................................................................................. 23
Read Device Information Sector (15H) .................................................................................................................... 24
SPECIAL SECTOR COMMANDS ................................................................................................................................. 24
Erase Sector (F1H) ................................................................................................................................................. 24
Erase Block (F4H) .................................................................................................................................................. 25
Write-only to Sector (F2H) ...................................................................................................................................... 25
COMPATIBILITY COMMANDS FOR 25xxxA SERIES DEVICES ................................................................................. 26
Read from SRAM (81H) .......................................................................................................................................... 26
Read Configuration Register (8BH) ......................................................................................................................... 27
Read Status Register (83H) .................................................................................................................................... 27
Transfer Sector to SRAM Clocked (54H) ................................................................................................................. 28
Compare Sector to SRAM Clocked (86H) ............................................................................................................... 28
Sector Format ........................................................................................................................................................ 29
High Data Integrity Applications .............................................................................................................................. 29
Write/Verify Flow .................................................................................................................................................... 29
Grouping Static and Frequently
Updated Data .......................................................................................................................................................... 29
ABOSOLUTE MINIMUM RATINGS .............................................................................................................................. 30
OPERATING RANGES ................................................................................................................................................. 30
DC ELECTRICAL CHARACTERISTICS (Preliminary) ................................................................................................. 30
AC ELECTRICAL CHARACTERISTICS (Preliminary) ................................................................................................. 31
SERIAL OUTPUT TIMING ............................................................................................................................................ 32
SERIAL INPUT TIMING ................................................................................................................................................ 32
HOLD TIMING .............................................................................................................................................................. 32
PACKAGING INFORMATION ........................................................................................................................................ 33
200-mil Plastic SOIC Package Code: (S) ............................................................................................................ 33
PACKAGING INFORMATION ........................................................................................................................................ 34
330 mil Plastic SOIC Package Code: (J) ............................................................................................................ 34
PACKAGING INFORMATION ........................................................................................................................................ 35
Plastic TSOP - 28-pins Package Code: Type I (V) ............................................................................................... 35
PRELIMINARY DESIGNATION .................................................................................................................................... 36
IMPORTANT NOTICE ................................................................................................................................................... 36
ORDERING INFORMATION ......................................................................................................................................... 36
LIFE SUPPORT POLICY ............................................................................................................................................. 36
Trademarks: ................................................................................................................................................................. 36
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NexFlash Technologies, Inc.
PRELIMINARY
NXSF016F-1201
12/12/01
NX25F011B
NX25F021B
NX25F041B
FEATURES
Flash Storage for Resource-Limited Systems
Ideal for portable/mobile and microcontroller-based
applications that store voice, text, and data
0.35
NexFlash
Memory Technology
1M/2M/4M-bit with 512/1024/2048 sectors
Small 264-byte sectors
Erase/Write time of 7.5 ms/sector (typical)
Optional 8KB (32 sector) block erase for faster
programming
Ultra-low Power for Battery-Operation
Single 5V or 3V supply for read and erase/write
1 mA standby current, 2.5 mA active @ 3V (typical)
Low frequency read command for lower power
4-pin SPI Serial Interface
Easily interfaces to popular microcontrollers
Clock operation as fast as 20 MHz
On-chip Serial SRAM
Single 264-byte Read/Write SRAM buffer
Use in conjunction with or independent of Flash
Off-loads RAM-limited microcontrollers
Special Features for Media-Storage Applications
Byte-level addressing for reads and SRAM writes
Transfer or compare sector to SRAM
Versatile hardware and software write-protection
In-system electronic part number option
Removable Serial Flash Module package option
Serial Flash Development Kit
DESCRIPTION
The NX25F011B, NX25F021B, and NX25F041B Serial
Flash memories provide a storage solution for systems
limited in power, pins, space, hardware, and firmware
resources. They are ideal for applications that store voice,
text, and data in a portable or mobile environment. Using
NexFlash's patented single transistor EEPROM cell, the
devices offer a high-density, low-voltage, low-power, and
cost-effective non-volatile memory solution. The devices
operate on a single 5V or 3V (2.7V-3.6V) supply for Read
and Erase/Write with typical current consumption as low as
2.5 mA active and less than 1
A standby. Sector
erase/write speeds as fast as 7.5 ms increase system
performance, minimize power-on time, and maximize
battery life.
The NX25F011B, NX25F021B, and NX25F041B provide
1M-bit, 2M-bit, and 4M-bit of flash memory organized as 512,
1024, or 2048 sectors of 264 bytes each. Each sector is
individually addressable through basic serial-clocked com-
mands. The 4-pin SPI serial interface works directly with
popular microcontrollers. Special features include: on-chip
serial SRAM, byte-level addressing, double-buffered sector
writes, transfer/compare sector to SRAM, hardware and
software write protection, alternate oscillator frequency, elec-
tronic part number, and removable Serial Flash Module
package option. Development is supported with the
PC-based SFK-SPI Serial Flash Development Kit.
NX25F011B
NX25F021B
NX25F041B
NexFlash Technologies, Inc.
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PRELIMINARY
NXSF016F-1201
12/12/01
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FUNCTIONAL OVERVIEW
An architectural block diagram of the NX25F011B,
NX25F021B, and NX25F041B is shown in Figure 2. Key
elements of the architecture include:
SPI Interface and Command Set Logic
Serial Flash Memory Array
Serial SRAM and Program Buffer
Write Protection Logic
Configuration and Status Registers
Device Information Sector
DEVICE INFORMATION SECTOR (DIS)
(READ ONLY)
WRITE PR
O
TECT LOGIC
NexFlash
1, 2 AND 4 M-BIT
SERIAL FLASH MEMORY ARRAY
512, 1024 AND 2048
BYTE-ADDRESSABLE
SECTORS OF 264 BYTES EACH
ORGANIZED IN 16, 32, AND 64
BLOCKS OF 32 SECTORS PER BLOCK
R
O
W DECODE (
512, 1024 AND 2048
SECT
ORS)
2112
8
8
8
SRAM (264 BYTES)
COLUMN DECODE, SENSE AMP LATCH
AND DATA COMPARE LOGIC
HIGH-VOLTAGE
GENERATORS
SECTOR-ADDRESS
LATCH
DATA
9/10/11
WRITE CONTROL
LOGIC
WP
HOLD OR
READ/BUSY
LOGIC
CONFIGURATION
REGISTER
STATUS
REGISTER
SPI
COMMAND
AND
CONTROL
LOGIC
BYTE-ADDRESS
LATCH/COUNTER
9
16
HOLD
OR R/
B
SCK
CS
SI
SO
Figure 2. NX25F011B, NX25F021B, and NX25F041B Architectural Block Diagram
Pin Descriptions
Package
The NX25F011B, NX25F021B, and NX25F041B are
available in a 28-pin TSOP (Type I) surface mount package.
The NX25F011B and NX25F021B are available in either an
8-pin SOIC and a 14-pin TSOP package (contact NexFlash
for information on the 14-pin TSOP package). The
NX25F041B is also available in a 28-pin SOIC package.
See Figure 3A, 3B and Table 1 for pin assignments. All
interface and supply pins are on one side of the TSOP
package. The "No Connect" (NC) pins are not connected to
the device, allowing the pads and the area around them to
be used for routing PCB system traces. The devices are
also available in a cost-effective and space-efficient
removable Serial Flash Module package.
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