NexFlash Technologies, Inc.
1
PRELIMINARY
NXSF022F-0502
05/20/02
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 2002, NexFlash Technologies, Inc.
PRELIMINARY
APRIL 2002
NX25F640C
64M-BIT SERIAL FLASH MEMORY
WITH 4-PIN SPI INTERFACE
NX25F640C
2
NexFlash Technologies, Inc.
PRELIMINARY
NXSF022F-0502
05/20/02
Table of Contents
64M-BIT SERIAL FLASH MEMORY
WITH 4-PIN SPI INTERFACE ........................................................................................................................................ 1
FEATURES .................................................................................................................................................................... 4
DESCRIPTION ............................................................................................................................................................... 4
Pin Descriptions ..................................................................................................................................................... 6
Serial Data Input (SI) ........................................................................................................................................... 6
Serial Data Output (SO) ....................................................................................................................................... 6
Chip Select (CS) .................................................................................................................................................. 6
Write Protect Input (WP) ...................................................................................................................................... 6
Hold , Ready/Busy or No-connect
(Hold, R/B or N/C) ................................................................................................................................................ 6
Power Supply Pins (Vcc and Gnd) ....................................................................................................................... 6
Table 1. Pin Descriptions for the 25F640 ............................................................................................................. 6
Serial Flash Memory Array .................................................................................................................................... 7
Restricted Sector (-R) Devices .............................................................................................................................. 7
Serial SRAM ............................................................................................................................................................ 8
Using the SRAM Independent of Flash Memory .................................................................................................. 8
Write Protection ..................................................................................................................................................... 9
Configuration Register .......................................................................................................................................... 9
Write Protect Range and Direction, WR[3:0], WD ................................................................................................ 9
Read Clock Edge, RCE ....................................................................................................................................... 9
HOLD-R/B, HR[1:0] ........................................................................................................................................... 10
Table 2. Write Protect Range Sector Selection .................................................................................................. 10
Status Register Bit Descriptions ........................................................................................................................ 10
Ready/Busy Status, BUSY ................................................................................................................................ 10
SRAM Transfer, TR0 and TR1 ............................................................................................................................ 10
Write Enable/Disable, WE .................................................................................................................................. 11
Power Detect, PD .............................................................................................................................................. 11
Data Intergrity Status (DI1, DI0) ........................................................................................................................ 11
Command Set ....................................................................................................................................................... 12
Table 3: Command Set for the NX25F640C Serial Flash Memory ..................................................................... 13
SERIAL FLASH SECTOR AND SRAM READ COMMANDS ...................................................................................... 15
Transfer Sector to SRAM (5CH and 5DH) ........................................................................................................... 15
Read SRAM (71H and 73H) .................................................................................................................................. 15
NX25F640C
NexFlash Technologies, Inc.
3
PRELIMINARY
NXSF022F-0502
05/20/02
Table of Contents
SERIAL FLASH SECTOR AND SRAM WRITE COMMANDS ..................................................................................... 16
Write Enable (06H) ............................................................................................................................................... 16
Write Disable (04H) .............................................................................................................................................. 16
Write to Sector Using SRAM (F6H or 98H) ......................................................................................................... 16
Write to SRAM Command (72H and 74H) ........................................................................................................... 17
TRANSFER AND REFRESH COMMANDS ................................................................................................................. 17
Transfer SRAM to Sector (F6H and 98H) ............................................................................................................ 17
Refresh Sector Using SRAM (58H and 59H) ...................................................................................................... 17
CONFIGURATION AND STATUS COMMANDS .......................................................................................................... 17
Read Device Information Sector (15H) ............................................................................................................... 17
Read Configuration Register (8CH) .................................................................................................................... 17
Write Configuration Register (8AH) .................................................................................................................... 17
Read Status Register (84H) ................................................................................................................................. 18
Clear Power Detection Bit (09H) ......................................................................................................................... 18
ABSOLUTE MAXIMUM RATINGS ............................................................................................................................... 19
OPERATING RANGES ................................................................................................................................................ 19
DC ELECTRICAL CHARACTERISTICS (Preliminary) ............................................................................................... 19
AC ELECTRICAL CHARACTERISTICS (Preliminary) ............................................................................................... 20
SERIAL OUTPUT TIMING ........................................................................................................................................... 21
SERIAL INPUT TIMING ............................................................................................................................................... 21
HOLD TIMING .............................................................................................................................................................. 21
Plastic TSOP - 32-pins ................................................................................................................................................ 22
Package Code: T (Type I) ................................................................................................................................... 22
PRELIMINARY DESIGNATION .................................................................................................................................... 23
IMPORTANT NOTICE .................................................................................................................................................. 23
ORDERING INFORMATION ........................................................................................................................................ 23
LIFE SUPPORT POLICY ............................................................................................................................................. 23
Trademarks: ................................................................................................................................................................ 23
NX25F640C
4
NexFlash Technologies, Inc.
PRELIMINARY
NXSF022F-0502
05/20/02
FEATURES
64M-bit Serial Flash Memory
Flash storage for systems with limited pins,
space, and power
- Ideal for high density serial code-download
- Data, voice and image storage
- Battery-operated products
Nonvolatile Memory Technology
- Single transistor EEPROM memory
- 16,384 sectors of 522 bytes each
- Sector erase/write time of 10 ms/sector (typical)
- Ten year data retention
4-pin SPI Serial Interface
- Easily interfaces to popular microcontrollers
- Clock operation as fast as 16MHz
- Optional Hold and Ready/Busy pin functions
Ultra-low Power for Battery-Operation
- Single 2.7-3.6V supply for Read, Erase/Write
- 1 A standby, 5 mA active (typical)
Special Features
- Two on-board 522-byte SRAM Buffers
- Byte-level addressing
- Configurable software write-protection
Package Options
- 32-PIN TSOP (Type I)
- Removable Cards and Modules
DESCRIPTION
The NX25F640C Serial Flash memory provide a storage
solution for systems which are limited in power, pins,
space, hardware and firmware resources. The NX25F640C
is ideal for applications that store voice, images and data
in a portable/mobile environment as well for down-loading
code into controllers with embedded DRAM or SRAM. The
NX25F640C operates on a single 2.7V-3.6V power supply
for read and erase/write with typical current
consumption as low as 5mA active and less than 1uA
standby. The array is organized into 16,384 sectors of 522
bytes each. Sector erase/write speeds are as fast as
10ms. The 4-pin SPI serial interface works directly with
popular micro-controllers. Special features include dual
on-chip serial SRAM, byte-level addressing, hardware/
software write protection and removable Serial Flash
Module packaging option. Development is supported with
the PC-based NexFlash Serial Flash Development Kit.
NX25F640C
NexFlash Technologies, Inc.
5
PRELIMINARY
NXSF022F-0502
05/20/02
25 SERIES
SPI
DEVICE INFORMATION SECTOR
(READ ONLY)
WRITE PR
O
TECT LOGIC
(16 RANGES)
64 MEGABIT
SERIAL FLASH MEMORY ARRAY
16,384 BYTE-ADDRESSABLE
SECTORS OF 522 BYTES EACH
ORGANIZED IN 256 BLOCKS OF
64 SECTORS PER BLOCK
R
O
W DECODE
SRAM BUFFER 2
(522 BYTES)
4176
STATE MACHINE AND CONTROL LOGIC
HIGH-VOLTAGE
GENERATORS
SECTOR-ADDRESS
LATCH
DATA
14
WRITE CONTROL
LOGIC
WP
HOLD OR
READ/BUSY
LOGIC
CONFIGURATION
REGISTER
STATUS
REGISTER
COMMAND AND
CONTROL LOGIC
BYTE-ADDRESS
LATCH/COUNTER
10
256
HOLD
OR R/
B
SCK
CS
SI
SO
SRAM BUFFER 1
(522 BYTES)
PAGE LATCH / BUFFER
Figure 1. NX25F640C Architectural Block Diagram
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