sri4k STMicroelectronics, sri4k Datasheet - Page 19

• Manufacturer Part Number: sri4k
• Description: 13.56 Mhz Short-range Contactless Memory Chip With 4096-bit Eeprom And Anticollision Functions
• Manufacturer: STMicroelectronics

SRI4K
4.4.1
4.4.2
OTP_Lock_Reg
The 8 bits, b
bits in the SRI4K. They control the Write access to the 9 EEPROM blocks with addresses 7
to 15 as follows:
The OTP_Lock_Reg bits cannot be erased. Once Write-protected, EEPROM blocks behave
like ROM blocks and cannot be unprotected.
Fixed Chip_ID (Option)
The SRI4K is provided with an anticollision feature based on a random 8-bit Chip_ID. Prior
to selecting an SRI4K, an anticollision sequence has to be run to search for the Chip_ID of
the SRI4K. This is a very flexible feature, however the searching loop requires time to run.
For some applications, much time could be saved by knowing the value of the SRI4K
Chip_ID beforehand, so that the SRI4K can be identified and selected directly without
having to run an anticollision sequence. This is why the SRI4K was designed with an
optional mask setting used to program a fixed 8-bit Chip_ID to bits b
area. When the fixed Chip_ID option is used, the random Chip_ID function is disabled.
–
–
–
–
–
–
–
–
When b
When b
When b
When b
When b
When b
When b
When b
31
to b
24
25
26
27
28
29
30
31
24
is at 0, blocks 7 and 8 are Write-protected
is at 0, block 9 is Write-protected
is at 0, block 10 is Write-protected
is at 0, block 11 is Write-protected
is at 0, block 12 is Write-protected
is at 0, block 13 is Write-protected
is at 0, block 14 is Write-protected
is at 0, block 15 is Write-protected.
, of the System Area (block address 255) are used as OTP_Lock_Reg
7
to b
Memory mapping
0
of the system
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