Rockwell Automation 56RF RFID System User Manual - Manual (Page 24)

24 Rockwell Automation Publication 56RF-UM001A-EN-P - October 2011
Chapter 2 RFID Components
Ferroelectric Random Access Memory (FRAM)
FRAM is a non-volatile memory that uses ferroelectric film as a capacitor for
storing data. FRAM offers high speed access, high endurance in write mode, low
power consumption, non-volatility, and excellent tamper resistance. The FRAM
tags have 2000 bytes for use as user area and 48 bytes for use as system area.
The FRAM tag memory areas consist of a total of 256 blocks (250 blocks of user
area and 6 blocks of system area). Each block can store 64 bits (8 bytes) of data.
The block is the unit used for the writing and reading of FRAM data. The
memory configuration of FRAM is shown below.
Table 14 - FRAM Memory Configuration
Blocks 00
H
…F9
H
are user area. The user area is defined as an area that can be
accessed when the corresponding block address is specified. On the other hand,
Blocks FA
H
…FF
H
are system area. The system area is defined as an area that can
be accessed only with a specific command.
The system area consists of six blocks and contains UUID, AFI, DSFID, EAS
bits, and security status (can write or cannot write) data for individual block.
UID is fixed and cannot be updated. AFI, DSFID, and EAS bits are written at
the factory, and can be updated and locked (disable to write) with commands
(only EAS bit cannot be locked) .
As shown in above, FA
H
holds the UUID, and FC
H
…FF
H
hold the security
status information on individual user areas. The configuration of FB
H
…FF
H
blocks is shown below. FB
H
block is used for EAS status, AFI and DSFID data,
the security status data of AFI and DSFID. Blocks FC
H
…FF
H
contain security
status data.
Table 15 - Structure of FB
H
Area Block No. Details Data Read Data Write
User area
(2000 bytes) 00
H
to F9
H
User area Yes Yes
System area
(48 bytes) FA
H
UUID (64 bits) Yes No
FB
H
AFI, DSFID, EAS,
security status Yes Limited
FC
H
to FF
H
Block security status Yes No
MSB LSB
64 57 56 33 32 25 24 17 16 9 8 1
EAS Status Reserved for
future use DSFID Lock
Status AFI Lock Status DSFID AFI