Electronic Components Datasheet Search |
|
X24F064S Datasheet(PDF) 9 Page - Xicor Inc. |
|
X24F064S Datasheet(HTML) 9 Page - Xicor Inc. |
9 / 18 page X24F064/032/016 9 PROGRAM PROTECT REGISTER The Program Protect Register (PPR) is accessed at the highest address of each device: X24F064 = 1FFF X24F032 = 0FFF X24F016 = 07FF Figure 10. Program Protect Register PPR.1 = WEL – Write Enable Latch (Volatile) 0 = Write enable latch reset, programming disabled 1 = Write enable latch set, programming enabled If WEL = 0 then “no ACK” after first byte of input data. PPR.2 = RWEL – Register Write Enable Latch (Volatile) 0 = Register write enable latch reset, programming disabled 1 = Register write enable latch set, programming enabled PPR.3, PPR.4 = BL0, BL1 – Block Lock Bits (Nonvolatile) (See Block Lock Bits section for definition) PPR.7 = PPEN – Programming Protect Enable Bit (Nonvolatile) (See Programmable Hardware Program Protect sec- tion for definition) Writing to the Program Protect Register The Program Protect Register is written by performing a write of one byte directly to the highest address loca- tion. During normal Sector Programming, the byte in the array at the highest address will be written instead of the Program Protect Register (assuming program- ming is not disabled by the Block Lock register). The state of the Program Protect Register can be read by performing a random read at the highest address location at any time. If a sequential read starting at any 7 6 5 4 3 2 1 0 PPEN 0 0 BL1 BL0 RWEL WEL 0 6686 ILL F15 other address than the highest address location is performed, the contents of the byte in the array at the highest address location is read out instead of the Program Protect Register. WEL and RWEL are volatile latches that power-up in the LOW (disabled) state. A write to any address other than the highest address location, where the Program Protect Register is located, will be ignored (no ACK) until the WEL bit is set HIGH. The WEL bit is set by writing 0000001x to the highest address location. Once set, WEL remains HIGH until either reset (by writing 00000000 to the highest address location) or until the part powers-up again. The RWEL bit controls writes to the Block Lock bits. RWEL is set by first setting WEL = 1 and then writing 0000011x to the highest address location. RWEL must be set in order to change the Block Lock bits (BL0 and BL1) or the PPEN bit. RWEL is reset when the Block Lock or PPEN bits are changed, or when the part powers-up again. Programming the BL or PPEN Bits A three step sequence is required to change the nonvolatile Block Lock or Program Protect Enable: 1) Set WEL = 1 (write 00000010 to the highest address location, volatile write cycle) (Start) 2) Set RWEL = 1 (write 00000110 to the highest address location, volatile write cycle) (Start) 3) Set BL1, BL0, and/or PPEN bits (Write w00yz010 to the highest address location) w = PPEN, y = BL1, Z = BL0, (Stop) Step 3 is a nonvolatile program cycle, requiring 10ms to complete. RWEL is reset (0) by this program cycle, requiring another program cycle to set RWEL again before the Block Lock bits can be changed. RWEL must be 0 in step 3; if w00yz110 is written to the highest address location, RWEL is set but PPEN, BL1 and BL0 are not changed (the device remains at step 2). |
Similar Part No. - X24F064S |
|
Similar Description - X24F064S |
|
|
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 |