 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
25AA640 Datasheet(PDF) 11 Page - Microchip Technology |
|
||||||||||||||||||||||||||||||
25AA640 Datasheet(HTML) 11 Page - Microchip Technology |
|
|
11 / 24 page  2004 Microchip Technology Inc. DS21223G-page 11 25AA640/25LC640 3.6 Write Status Register Instruction (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 reg- ister. 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 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 program- mable hardware write-protect feature. Hardware write protection is enabled when the 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 3-3 for a matrix of functionality on the WPEN bit. See Figure 3-7 for WRSR timing sequence. TABLE 3-2: ARRAY PROTECTION FIGURE 3-7: WRITE STATUS REGISTER TIMING SEQUENCE BP1 BP0 Array Addresses Write-Protected 00 none 01 upper 1/4 (1800h-1FFFh) 10 upper 1/2 (1000h-1FFFh) 11 all (0000h-1FFFh) SO SI CS 9 1011 12 131415 01 0 0 0 0 00 76 5 4 21 0 Instruction Data to Status Register High-impedance SCK 0 23456 7 1 8 3 |
Similar Part No. - 25AA640_04 |
|
Similar Description - 25AA640_04 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
