参数资料
型号: AT45DB021D-SSU
厂商: ATMEL CORP
元件分类: DRAM
英文描述: 2-megabit 2.7-volt DataFlash
中文描述: 2M X 1 FLASH 2.7V PROM, PDSO8
封装: 0.150 INCH, GREEN, PLASTIC, MS-012AA, SOIC-8
文件页数: 18/52页
文件大小: 1108K
代理商: AT45DB021D-SSU
18
3638B–DFLASH–02/07
AT45DB021D [Preliminary]
10. Security Features
10.1
Sector Lockdown
The device incorporates a Sector Lockdown mechanism that allows each individual sector to be
permanently locked so that it becomes read only. This is useful for applications that require the
ability to permanently protect a number of sectors against malicious attempts at altering program
code or security information.
Once a sector is locked down, it can never be erased or pro-
grammed, and it can never be unlocked.
To issue the Sector Lockdown command, the CS pin must first be asserted as it would be for
any other command. Once the CS pin has been asserted, the appropriate 4-byte opcode
sequence must be clocked into the device in the correct order. The 4-byte opcode sequence
must start with 3DH and be followed by 2AH, 7FH, and 30H. After the last byte of the command
sequence has been clocked in, then three address bytes specifying any address within the sec-
tor to be locked down must be clocked into the device. After the last address bit has been
clocked in, the CS pin must then be deasserted to initiate the internally self-timed lockdown
sequence.
The lockdown sequence should take place in a maximum time of t
P
, during which time the Status
Register will indicate that the device is busy. If the device is powered-down before the comple-
tion of the lockdown sequence, then the lockdown status of the sector cannot be guaranteed. In
this case, it is recommended that the user read the Sector Lockdown Register to determine the
status of the appropriate sector lockdown bits or bytes and reissue the Sector Lockdown com-
mand if necessary.
Figure 10-1.
Sector Lockdown
Command
Byte 1
Byte 2
Byte 3
Byte 4
Sector Lockdown
3DH
2AH
7FH
30H
Opcode
Byte 1
Opcode
Byte 2
Opcode
Byte 3
Opcode
Byte 4
CS
Address
Bytes
Address
Bytes
Address
Bytes
Each transition
represents
8
b
its
SI
相关PDF资料
PDF描述
AT45DB021D-SU 2-megabit 2.7-volt DataFlash
AT45DB021 2-Megabit 2.7-volt Only Serial DataFlash
AT45DB021-JC 2-Megabit 2.7-volt Only Serial DataFlash
AT45DB021-JI 2-Megabit 2.7-volt Only Serial DataFlash
AT45DB021-RC 2-Megabit 2.7-volt Only Serial DataFlash
相关代理商/技术参数
参数描述
AT45DB021D-SU 功能描述:闪存 2M SERIAL 2.7V - IND TEMP 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
AT45DB021E-MHD-T 功能描述:闪存 2 Megabit 2.7V-3.6V 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
AT45DB021E-MHD-Y 功能描述:闪存 2 Megabit 2.7V-3.6V 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
AT45DB021E-MHN2B-T 制造商:Adesto Technologies Corporation 功能描述:8-UDFN (5X6), IND TEMP, 1.65V, T&R, 256 BYTE PAGE - Tape and Reel 制造商:Adesto Technologies Corporation 功能描述:IC FLASH 2MBIT 70MHZ 8UDFN
AT45DB021E-MHN-T 功能描述:闪存 2M 1.65-3.6V 70Mhz Serial 闪存 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