25AA320/25LC320/25C320
3.6
Write Status Register Instruction
When the chip is hardware write-protected, only writes
( WRSR )
The Write Status Register instruction ( WRSR ) allows the
user to select one of four levels of protection for the
array by writing to the appropriate bits in the STATUS
to nonvolatile bits in the STATUS register are disabled.
See Table 3-3 for a matrix of functionality on the WPEN
bit.
See Figure 3-7 for the WRSR timing sequence.
register. The array is divided up into four segments.
The user has the ability to write-protect none, one, two,
TABLE 3-2:
ARRAY PROTECTION
or all four of the segments of the array. The partitioning
is controlled as shown in Table 3-2.
The Write-Protect Enable (WPEN) bit is a nonvolatile
bit that is available as an enable bit for the WP pin. The
Write-Protect (WP) pin and the Write-Protect Enable
(WPEN) bit in the STATUS register control the pro-
grammable hardware write-protect feature. Hardware
write protection is enabled when WP pin is low and the
WPEN bit is high. Hardware write protection is disabled
when either the WP pin is high or the WPEN bit is low.
BP1
0
0
1
1
BP0
0
1
0
1
Array Addresses
Write-Protected
none
upper 1/4
(0C00h-0FFFh)
upper 1/2
(0800h-0FFFh)
all
(0000h-0FFFh)
FIGURE 3-7:
CS
WRITE STATUS REGISTER TIMING SEQUENCE
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
SCK
Instruction
Data to STATUS Register
SI
0
0
0
0
0
0
0
1
7
6
5
4
3
2
1
0
High-Impedance
SO
? 2008 Microchip Technology Inc.
DS21227F-page 11
相关PDF资料
25LC010AT-E/MC IC EEPROM 1KBIT 10MHZ 8DFN
25LC040AT-E/MC IC EEPROM 4KBIT 10MHZ 8DFN
25LC080A-I/STG IC EEPROM 8KBIT 10MHZ 8TSSOP
25LC1024T-E/MF IC EEPROM 1MBIT 20MHZ 8DFN
25LC128-E/MF IC EEPROM 128KBIT 10MHZ 8DFN
25LC160/P IC EEPROM 16KBIT 2MHZ 8DIP
25LC160B-I/PG IC EEPROM 16KBIT 10MHZ 8DIP
25LC256T-E/MF IC EEPROM 256KBIT 10MHZ 8DFN
相关代理商/技术参数
25C320-E/PG 功能描述:电可擦除可编程只读存储器 4kx8 - 5V Lead Free Package RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
25C320E/SN 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:32K SPI Bus Serial EEPROM
25C320-E/SN 功能描述:电可擦除可编程只读存储器 4kx8 - 5V RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
25C320-E/SNG 功能描述:电可擦除可编程只读存储器 4kx8 - 5V Lead Free Package RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
25C320E/ST 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:32K SPI Bus Serial EEPROM
25C320-E/ST 制造商:未知厂家 制造商全称:未知厂家 功能描述:SPI Serial EEPROM
25C320E/ST14 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:32K SPI Bus Serial EEPROM
25C320-E/ST14 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:32K SPI Bus Serial EEPROM