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参数资料
| 型号： | AT49F002AT |
| 厂商： | Atmel Corp. |
| 英文描述： | 2-megabit (256K x 8) 5-volt Only Flash Memory |
| 中文描述： | 2兆位（256K × 8）5伏只有闪存 |
| 文件页数： | 5/20页 |
| 文件大小： | 213K |
| 代理商： | AT49F002AT |
5
3354F–FLASH–2/05
AT49F002A(N)(T)
4.5
Byte Programming
Once the memory array is erased, the device is programmed (to a logical “0”) on a byte-by-byte
basis. Please note that a data “0” cannot be programmed back to a “1”; only erase operations
can convert “0”s to “1”s. Programming is accomplished via the internal device command register
and is a 4 bus cycle operation (please refer to the Command Definitions table). The device will
automatically generate the required internal program pulses.
The program cycle has addresses latched on the falling edge of WE or CE, whichever occurs
last, and the data latched on the rising edge of WE or CE, whichever occurs first. Programming
is completed after the specified t
BP
cycle time. The DATA polling feature may also be used to
indicate the end of a program cycle.
4.6
Boot Block Programming Lockout
The device has one designated block that has a programming lockout feature. This feature pre-
vents programming of data in the designated block once the feature has been enabled. The size
of the block is 16K bytes. This block, referred to as the boot block, can contain secure code that
is used to bring up the system. Enabling the lockout feature will allow the boot code to stay in the
device while data in the rest of the device is updated. This feature does not have to be activated;
the boot block’s usage as a write protected region is optional to the user. The address range of
the boot block is 00000 to 03FFF for the AT49F002A(N) while the address range of the boot
block is 3C000 to 3FFFF for the AT49F002A(N)T.
Once the feature is enabled, the data in the boot block can no longer be erased or programmed
with input voltage levels of 5.5V or less. Data in the main memory block can still be changed
through the regular programming method. To activate the lockout feature, a series of six pro-
gram commands to specific addresses with specific data must be performed. Please refer to the
Command Definitions table.
4.6.1
Boot Block Lockout Detection
A software method is available to determine if programming of the boot block section is locked
out. When the device is in the software product identification mode (see Software Product Iden-
tification Entry and Exit sections) a read from address location 00002H will show if programming
the boot block is locked out for the AT49F002A(N), and a read from address location 3C002H
will show if programming the boot block is locked out for AT49F002A(N)T. If the data on I/O0 is
low, the boot block can be programmed; if the data on I/O0 is high, the program lockout feature
has been activated and the block cannot be programmed. The software product identification
exit code should be used to return to standard operation.
4.6.2
Boot Block Programming Lockout Override
The user can override the boot block programming lockout by taking the RESET pin to 12 volts.
By doing this, protected boot block data can be altered through a chip erase, sector erase or
word programming. When the RESET pin is brought back to TTL levels the boot block program-
ming lockout feature is again active. This feature is not available on the AT49F002AN(T).
相关PDF资料 |
PDF描述 |
|---|---|
| AT49F002AT-55JI | 2-megabit (256K x 8) 5-volt Only Flash Memory |
| AT49F002AT-55TI | LM4836 Boomer ® Audio Power Amplifier Series Stereo 2W Audio Power Amplifiers with DC Volume Control, Bass Boost, and Input Mux; Package: TSSOP; No of Pins: 28 |
| AT49F002AT-55VI | LM4836 Boomer ® Audio Power Amplifier Series Stereo 2W Audio Power Amplifiers with DC Volume Control, Bass Boost, and Input Mux; Package: TSSOP EXP PAD; No of Pins: 28 |
| AT49F002N | 2-Megabit 256K x 8 5-volt Only Flash Memory |
| AT49F002N-12TC | 2-Megabit 256K x 8 5-volt Only Flash Memory |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AT49F002AT-55JI | 功能描述:闪存 2M (256kx8) RoHS:否 制造商:ON Semiconductor 数据总线宽度:1 bit 存储类型:Flash 存储容量:2 MB 结构:256 K x 8 定时类型: 接口类型:SPI 访问时间: 电源电压-最大:3.6 V 电源电压-最小:2.3 V 最大工作电流:15 mA 工作温度:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体: 封装:Reel |
| AT49F002AT-55PI | 功能描述:IC FLASH 2MBIT 55NS 32DIP 制造商:microchip technology 系列:- 包装:管件 零件状态:停產 存储器类型:非易失 存储器格式:闪存 技术:FLASH 存储容量:2Mb （256K x 8） 写周期时间 - 字，页:50μs 访问时间:55ns 存储器接口:并联 电压 - 电源:4.5 V ~ 5.5 V 工作温度:-40°C ~ 85°C（TC） 安装类型:通孔 封装/外壳:32-DIP（0.600"，15.24mm） 供应商器件封装:32-DIP 基本零件编号:AT49F002 标准包装:12 |
| AT49F002AT-55TI | 功能描述:IC FLASH 2MBIT 55NS 32TSOP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:96 系列:- 格式 - 存储器:闪存 存储器类型:FLASH 存储容量:16M（2M x 8，1M x 16） 速度:70ns 接口:并联 电源电压:2.65 V ~ 3.6 V 工作温度:-40°C ~ 85°C 封装/外壳:48-TFSOP（0.724"，18.40mm 宽） 供应商设备封装:48-TSOP 包装:托盘 |
| AT49F002AT-55VI | 功能描述:IC FLASH 2MBIT 55NS 32VSOP RoHS:否 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:96 系列:- 格式 - 存储器:闪存 存储器类型:FLASH 存储容量:16M（2M x 8，1M x 16） 速度:70ns 接口:并联 电源电压:2.65 V ~ 3.6 V 工作温度:-40°C ~ 85°C 封装/外壳:48-TFSOP（0.724"，18.40mm 宽） 供应商设备封装:48-TSOP 包装:托盘 |
| AT49F002N | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:2-Megabit 256K x 8 5-volt Only Flash Memory |
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