Electronic Components Datasheet Search |
|
X46402V8E-2.9 Datasheet(PDF) 4 Page - Xicor Inc. |
|
X46402V8E-2.9 Datasheet(HTML) 4 Page - Xicor Inc. |
4 / 23 page X46402 Preliminary Information 4 Password Protection Configuration Portions of the memory array may be “locked”. This area of memory is password protected and is defined by the bits BL2, BL1 and BL0. For these protected areas it is necessary to use a Read password to output data and an “Array Write” Password to write data. This block lock area is re-writable, by issuing the correct password. SERIAL MEMORY OPERATION There are four primary modes of operation for the X46402; Protected READ and WRITE of the memory and OTP arrays and unprotected Read and Write of non- password protected areas of the memory array. Pro- tected operations must be performed with one of four 8- byte passwords. The basic method of communication for the password protected areas of the device is established by generat- ing a start condition, then transmitting a command, fol- lowed by the correct password. All parts will be shipped from the factory with all passwords equal to ‘0’. The user must perform ACK Polling to determine the validity of the password, before starting a data transfer (see Acknowl- edge Polling.) Only after the correct password is accepted and a ACK polling has been performed, can the data transfer occur. Non-password protected areas of the memory array are accessed in the same manner as access to password protected areas, except the password and the password acknowledge polling sequences are not required. Data is transferred in 8-bit segments, with each transfer being followed by an ACK, generated by the receiving device. If the X46402 is in a nonvolatile write cycle a “no ACK” (SDA=HIGH) response will be issued in response to loading of the command byte. If a stop is issued prior to the start of a nonvolatile write cycle the write operation will be terminated and the part will reset and enter into a standby mode. The basic sequence is illustrated in Figure 1. After each transaction is completed, the X46402 will reset and enter into a standby mode. This will also be the response if an unsuccessful attempt is made to access a protected array. Password Protection The X46402 requires a 64 bit write password to change the contents of the control register or to write to a block protected memory area. The X46402 also requires a 64 bit read password to output the contents of the block pro- tected array or the control register. The block protection is controlled by the [BL2:BL0] bits and allows the options described in Table 2. If an area is block protected, it needs a password prior to each read or write to the area. The passwords cannot be read, even after the device receives the correct password. Figure 1. X46402 Device Operation (Password Protected Areas) Table 2. Password Protected Block Size Select BL2 BL1 BL0 Password Protected Addresses (Use Password Command) Non-Password Protected Addresses (Use Password or No-Password Commands) 000 None 0000h - 1FFFh 001 0000h - 003Fh 0040h - 1FFFh 010 0000h - 007Fh 0080h - 1FFFh 011 0000h - 00FFh 0100h - 1FFFh 100 0000h - 01FFh 0200h - 1FFFh 101 0000h - 07FFh 0800h - 1FFFh 110 0000h - 0FFFh 1000h - 1FFFh 111 0000h - 1FFFh None LOAD COMMAND BYTE LOAD 2 BYTE ADDRESS LOAD 8-BYTE PASSWORD VERIFY PASSWORD ACCEPTANCE BY USE OF PASSWORD ACK POLLING READ/WRITE DATA BYTES Twc OR DATA ACK POLLING |
Similar Part No. - X46402V8E-2.9 |
|
Similar Description - X46402V8E-2.9 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |