25AA640A/25LC640A
2.6
Write Status Register Instruction
See Figure 2-7 for the WRSR timing sequence.
( WRSR )
The Write Status Register instruction ( WRSR ) allows the
TABLE 2-3:
ARRAY PROTECTION
user to write to the nonvolatile bits in the STATUS reg-
ister as shown in Table 2-2. The user is able to select
one of four levels of protection for the array by writing
to the appropriate bits in the STATUS register. The
array is divided up into four segments. The user has the
ability to write-protect none, one, two, or all four of the
segments of the array. The partitioning is controlled as
shown in Table 2-3.
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
BP1
0
0
1
1
BP0
0
1
0
1
Array Addresses
Write-Protected
none
upper 1/4
(1800h-1FFFh)
upper 1/2
(1000h-1FFFh)
all
(0000h-1FFFh)
(WPEN) bit in the STATUS register control the
programmable hardware write-protect feature. Hard-
ware 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. When the chip is hardware write-protected,
only writes to nonvolatile bits in the STATUS register
are disabled. See Table 2-4 for a matrix of functionality
on the WPEN bit.
FIGURE 2-7:
CS
WRITE STATUS REGISTER TIMING SEQUENCE ( WRSR )
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
Note:
An internal write cycle (T WC ) is initiated on the rising edge of CS after a valid write STATUS register
sequence.
? 2003-2012 Microchip Technology Inc.
DS21830E-page 11
相关PDF资料
281708-4 PLUG HE14 IDC 90 4 P TUBE
281709-4 PLUG HE13 IDC 90 4 P AWG 24
281711-2 PLUG HE14 IDC 90 2 P TUBE
281783-8 PLUG HE14 IDC 180 8 P AWG 26-24
281784-5 PLUG HE13 IDC 180 5 P AWG 26-24
281786-8 PLUG HE14 IDC 180 8 P AWG 28-26
281789-8 PLUG HE14 IDC 180 2X8 P AWG26-24
281792-3 PLUG HE14 IDC 180 2X3 P AWG28-26
相关代理商/技术参数
25LC640A-E/SN 功能描述:电可擦除可编程只读存储器 64K 8K X 8 25V SER EE EXT 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
25LC640A-E/SN 制造商:Microchip Technology Inc 功能描述:IC EEPROM 64KBIT SPI 10MHZ SOIC-8 制造商:Microchip Technology Inc 功能描述:IC, EEPROM, 64KBIT, SPI, 10MHZ, SOIC-8
25LC640A-E/ST 功能描述:电可擦除可编程只读存储器 64K 8K X 8 25V SER EE EXT 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
25LC640A-H/SN 功能描述:电可擦除可编程只读存储器 64K 8K X 8 2.5V SER EE 150C 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
25LC640A-I/MF 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:64K SPI Bus Serial EEPROM
25LC640A-I/MNY 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:64K SPI Bus Serial EEPROM
25LC640A-I/MS 功能描述:电可擦除可编程只读存储器 64K 8K X 8 25V SER EE IND 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
25LC640A-I/P 功能描述:电可擦除可编程只读存储器 64K 8KX8 2.5V SER EE IND 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