SRI4K-SBN181GE STMICROELECTRONICS [STMicroelectronics], SRI4K-SBN181GE Datasheet - Page 18

• Manufacturer Part Number: SRI4K-SBN181GE
• Description: 13.56 MHz short-range contactless memory chip with 4096-bit EEPROM and anticollision functions
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Memory mapping
4.4.1
4.4.2
18/45
Figure 18. System area
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
Block
address
255
31
24
25
26
27
28
29
30
31
MSb
OTP_Lock_Reg
b31
to b
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.
24
, of the System area (block address 255) are used as OTP_Lock_Reg
b24 b23
ST reserved
32-bit block
b16 b15
b8 b7
Fixed Chip_ID
(Option)
LSb
b0
7
to b
0
Description
of the system
OTP
ai07663b
SRI4K