WM72016-6 Datasheet, PDF (8/33 Pages) Cypress Semiconductor – 16Kbit Secure F-RAM Memory with Gen-2 RFID Access & Serial Port Direct Memory Access

WM72016-6 – Secure F-RAM with Gen-2 RFID and Serial Port
16-bit data words in reserved memory. The most significant ACCESS password is stored in reserved memory
bank address 0x02 with the least significant word stored in reserved memory bank address 0x03. Once the
access password has been set, it should be permanently locked using the LOCK command. The WM72016-6 is
shipped from the factory with the access password memory unlocked. The value of the access password has no
effect on the functionality of the DSPI serial port.
EPC Memory Bank:
The EPC memory bank accommodates 8 words: 1 protocol control (PC) word, a 6-word (96-bit) memory space
for an EPC identifier, and a 1-word CRC. The CRC word is calculated as part of the WM72016-6 power-on
initialization routine and written into the EPC memory bank address 0x00. The PC and 6-word EPC identifier
are completely programmable. The Protocol Control field is shown in Figure 4.
bit 15
11 10 9 8 7
0
PROTOCOL CONTROL WORD
LEN
UMI XPC NT
NSI
Numbering System Identifier
NSI Type
Extended Protocol Control
User Memory identifier
EPC Identifier Word Length
DEFAULT
00110
100
00000000
Figure 4. EPC Protocol Control Word
The five most significant bits of the PC indicates the size of the EPC identifier in words – for a 96-bit (6-word)
EPC identifier, the PC should be programmed to 0b0011_0xxx_xxxx_xxxx. The LEN parameter of the PC
word may not be greater than 0b00110 – a LEN parameter of 0b00000 has an EPC identifier length of zero
words resulting in only the PC and CRC words when WM72016-6 is acknowledged. The UMI bit (User
Memory Identifier) is asserted to a logic one by WM72016-6 and mapped to bit 10 of the PC word. In the
event the host writes a logic zero to the UMI bit, the memory location will be written with a logic zero,
however the backscattered EPC identifier will assert the UMI bit to a logic one which is also used in the
calculation of the CRC. WM72016-6 does not support extended protocol control and should be written with a
logic zero. PC word bits 8 down to 0 of the PC word are factory-initialized to zero. The WM72016-6 is
shipped from the factory with the EPC memory bank unlocked.
TID Memory Bank:
The TID memory bank consists of 4 words (64 bits), and is defined as shown in Table 2. The TID memory
bank is permanently locked at the factory and obeys the ISO/IEC 15963 numbering convention.
Document Number: 001-86227 Rev. **
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