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參數資料
型號: W49V002A
廠商: WINBOND ELECTRONICS CORP
英文描述: 256K x 8 CMOS FLASH MEMORY WITH LPC INTERFACE
中文描述: 256K × 8的CMOS閃存與LPC接口
文件頁數: 4/32頁
文件大?。?/td> 300K
代理商: W49V002A
W49V002FA
- 4 -
Program Operation
The W49V002FA is programmed on a byte-by-byte basis. Program operation can only change logical
data "1" to logical data "0." The erase operation, which changed entire data in main memory and/or
boot block from "0" to "1", is needed before programming.
The program operation is initiated by a 4-byte command cycle (see Command Codes for Byte
Programming). The device will internally enter the program operation immediately after the byte-
program command is entered. The internal program timer will automatically time-out (100
μ
S max. -
T
BP
) once it is completed and then return to normal read mode. Data polling and/or Toggle Bits can be
used to detect end of program cycle.
Boot Block Operation and Hardware Protection at Initial- #TBL & #WP
There are two alternatives to set the boot block. One is software command sequences method; the
other is hardware method. 16K-byte in the top location of this device can be locked as boot block,
which can be used to store boot codes. It is located in the last 16K bytes of the memory with the
address range from 3C000(hex) to 3FFFF(hex).
Please see Command Codes for Boot Block Lockout Enable for the specific code. Once this feature is
set, the data for the designated block cannot be erased or programmed (programming lockout), other
memory locations can be changed by the regular programming method.
Besides the software method, there is a hardware method to protect the top boot block and other
sectors. Before program/erase to this device, set the #TBL pin to low state and then the top boot block
will not be programmed/erased. When enabling hardware top boot block, #TBL being low state, it will
override the software method setting. That is, if #TBL is at low state, then top boot block cannot be
programmed/erased no matter how the software boot block lock setting.
Another pin, #WP, will protect the whole chip if this pin is set to low state before program/erase. The
enable of this pin will override the #TBL setting. That is, the top boot block cannot be
programmed/erased if this pin is set to low no matter how the #TBL or software boot block lock setting.
Hardware Data Protection
The integrity of the data stored in the W49V002FA is also hardware protected in the following ways:
(1) Noise/Glitch Protection: A #WE pulse of less than 15 nS in duration will not initiate a write cycle.
(2) V
DD
Power Up/Down Detection: The programming and read operation are inhibited when V
DD
is
less than 1.5V typical.
(3) Write Inhibit Mode: Forcing #OE low or #WE high will inhibit the write operation. This prevents
inadvertent writes during power-up or power-down periods.
(4) V
DD
power-on delay: When V
DD
has reached its sense level, the device will automatically time-out 5
mS before any write (erase/program) operation.
Data Polling (DQ
7
)- Write Status Detection
The W49V002FA includes a data polling feature to indicate the end of a program or erase cycle.
When the W49V002FA is in the internal program or erase cycle, any attempts to read DQ
7
of the last
byte loaded will receive the complement of the true data. Once the program or erase cycle is
completed, DQ
7
will show the true data. Note that DQ
7
will show logical "0" during the erase cycle, and
when erase cycle has been completed it becomes logical "1" or true data.
相關PDF資料
PDF描述
W49V002AP 256K x 8 CMOS FLASH MEMORY WITH LPC INTERFACE
W49V002AQ 256K x 8 CMOS FLASH MEMORY WITH LPC INTERFACE
W49V002FA 256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE
W49V002FAP 256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE
W49V002FAQ 256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE
相關代理商/技術參數
參數描述
W49V002AP 制造商:WINBOND 制造商全稱:Winbond 功能描述:256K x 8 CMOS FLASH MEMORY WITH LPC INTERFACE
W49V002AQ 制造商:WINBOND 制造商全稱:Winbond 功能描述:256K x 8 CMOS FLASH MEMORY WITH LPC INTERFACE
W49V002FA 制造商:WINBOND 制造商全稱:Winbond 功能描述:256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE
W49V002FAP 制造商:WINBOND 制造商全稱:Winbond 功能描述:256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE
W49V002FAQ 制造商:WINBOND 制造商全稱:Winbond 功能描述:256K X 8 CMOS FLASH MEMORY WITH FWH INTERFACE