STMICROELECTRONICS XRA00

XRA00
UHF, EPCglobal Class 1b, Contactless Memory Chip
96 bit ePC with Inventory and Kill Function
FEATURES SUMMARY
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ePCglobal Class 1b Specification
Passive Operation (No Battery Required)
UHF Carrier Frequencies From 860MHz to
960MHz ISM Band Which Comply To:
– North American Regulation
– European Regulation
– Similar Regulations in Other Countries
To the XRA00:
– Asynchronous 50% to 100% ASK
Modulation Using PWM Pulse Coding
(15K to 70Kbits/s)
From the XRA00:
– Backscattered rEflective Answers using
FSK bit coding (30K to 140Kbits/s)
128 bit EEPROM with Lock Bit
96 Bit ePC
Internal PLL for Data Transfer
Synchronisation
Inventory, Read, Prog and Erase features
Persistance Mode For Inventory Sequence
Optimisation
Kill Command
30ms Programming Time (typical)
More than 10,000 Write/Erase cycles
More than 40 Years’ Data Retention
October 2005
Figure 1. Delivery Forms
Unsawn unbumped wafers or
sawn and bumped wafers
1/40
XRA00
TABLE OF CONTENTS
FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 1. Delivery Forms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. Pad Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 1. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 3. Die Floor Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DATA TRANSFER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Input Data Transfer from the Reader to the XRA00 (Request Frame) . . . . . . . . . . . . . . . . . . . . 6
Figure 4. ASK Modulation of the Received Wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 5. ASK Pulse Modulation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Symbol Transmission Format for Request Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Request Binary Data "0" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Request Binary Data "1" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Bin pulse and Bin Response Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Transaction Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Power Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 6. Data Modulation Timing - “0” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 7. Data Modulation Timing - “1” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 8. Bin Response Window Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 9. Transaction Gap Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 10.Transaction after Power Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 2. Request Modulation Pulse Parameters for North American Operation (−20 to 55°C) . . . . 9
Table 3. Request Modulation Pulse Parameters for European Operation (−20 to 55°C) . . . . . . . . 10
Request Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 11.Reader to XRA00 Modulation Overview (Request Frame) . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 12.Data Modulation Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 13.Bin Modulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 14.Bin Modulation Timing details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Coast Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 15.Coast Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Ping Reply Bin Collapse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 16.Collapsed Ping Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Output Data Transfer from the XRA00 to the Reader. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Answer Binary Data Bits 0 and 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 17.XRA00 Answer Binary Data Bit Cell Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Answer Frame from the XRA00 to the Reader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 18.XRA00 Answer Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 19.Transmission of XRA00 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
XRA00 Answer Bit Cell Variation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 20.XRA00 Answer Bit Cell Variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 4. XRA00 Backscattered Answer Modulation Parameters . . . . . . . . . . . . . . . . . . . . . . . . . 14
Scroll Answer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2/40
XRA00
Figure 21.XRA00 Scroll Answer Duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 22.ScrollID Answer Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
PingID Answer Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 23.PingID Answer Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Contention Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 24.Contention of Two XRA00 Devices with the Same Clock Rate and a 1-Bit Difference . . 17
MEMORY MAPPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 25.XRA00 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
USER mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
COMMAND-REPLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
XRA00 State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power Up State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Awake State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Reply State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Asleep State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Dead State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 26.XRA00 State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
GENERAL COMMAND FORMAT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
READER COMMAND STRUCTURE - (REQUEST FRAME COMMAND FORMAT) . . . . . . . . . . . . . . 22
Table 5. Request Frame Command Field Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Command Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 6. Basic Command Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 7. Programming Command Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
BASIC COMMANDS - OVERVIEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ScrollID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Example of a ScrollID Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 8. Example of a ScrollID Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
ScrollID Answer Frame Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 27.ScrollID Answer Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
ScrollAllID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Example of a ScrollAllID Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 9. Example of a ScrollAllID Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
ScrollAllID Answer Frame Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 28.ScrollAllID Answer Frame Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Kill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 29.Kill Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
PingID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Example of a PingID Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 10. Example of PingID Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 30.PingID Answer Frame Structure for XRA00 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
PingID Answer Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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XRA00
Figure 31.PingID Answer Response Period - Reader Modulations Define Response Bins . . . . . . 29
Quiet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Example of a Quiet Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 11. Example of a Quiet Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 32.Example of a Quiet Request Frame Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Talk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Example Talk Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 12. Example of a Talk Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Figure 33.Example of aTalk Request Frame Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
PROGRAMMING COMMANDS - OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
VerifyID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
EraseID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
ProgramID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 13. Programming Row Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Lock Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 14. Row 7 of an Unlocked or Erased Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 15. Row 7 of a Locked Memory (Showing Lock Code A5h) . . . . . . . . . . . . . . . . . . . . . . . . . 32
EraseID and ProgramID Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 34.EraseID and ProgramID Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
ANTI-COLLISION ALGORITHM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 35.First Four LSBs as a Binary Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Anti-Collision Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 36.Reader Modulations and XRA00 Backscatter During PingID Reply for Query 1. . . . . . . 34
Figure 37.Query Tree for the Two PingID Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 38.Reader Modulations and XRA00 Backscatter During PingID Reply for Query 2. . . . . . . 35
ANTI-COLLISION FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
XRA00 IMPEDANCE PARAMETERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 16. XRA00 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 17. 6-inch Wafer XRA00 Impedance Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 18. 8-inch Wafer XRA00 Impedance Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 39.XRA00 Input Impedance, Equivalent Serial Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 19. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 20. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
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XRA00
SUMMARY DESCRIPTION
The XRA00 is a low-cost integrated circuit for use
in Radio Frequency Identification (RFID) transponders (tags) operating at UHF frequencies. It is
a 128 bit memory organized as 8 blocks of 16 bits
as shown in Table 5.
When connected to an antenna, the operating
power is derived from the RF energy produced by
the RFID Reader. Incoming data are demodulated
and decoded from the received Amplitude Shift
Keyed (ASK) signal and outgoing data are generated by the antenna reflectivity change using the
Frequency Shift Keying (FSK) coding principle.
The Data transfer rate is determined by the local
UHF frequency regulation.
The XRA00 follows the ePCglobal Class 1b UHF
recommendation for the radio-frequency power
and signal interface.
Figure 2. Pad Connections
Power
Supply
Regulator
128 Mbit
EEPROM
ASK
Memory Demodulator
AC1
AC0
Reflecting
Modulator
ai10741
The dialogue between the Reader and the XRA00
is conducted through the following consecutive
operations:
■
activation of the XRA00 by the UHF operating
field of the Reader
■
transmission of a command by the Reader
■
transmission of a response by the XRA00
This technique is called Reader Talk First (RTF).
Table 1. Signal Names
AC1
Antenna Pad
AC0 (GND)
Antenna Pad
The XRA00 is specifically designed for extented
range applications that need automatic item identification. The XRA00 provides a fast and flexible
anti-collision protocol that is robust under noisy
and unpredictable RF conditions typical of RFID
applications. It is based on a determinist binary
tree scanning method accelerated by bin slot distribution. The XRA00 EEPROM memory can be
read and written, so that the users can program
the ePC code themselves, if desired.
The XRA00 has the following command set:
– SCROLLID: XRA00, matching data sent by the
Reader, replies by sending back the entire ID
Code. This command is used during the anticollision sequence.
– SCROLLALLID: XRA00 replies in an indiscriminate way by sending back the entire ID Code.
– PINGID: This command is used as part of a
multi-XRA00 anti-collision sequence. XRA00,
matching data sent by the Reader, responds in
one of the eight specific bin slots.
– QUIET: XRA00, matching data sent by the
Reader, enters the Asleep state where it no
longer responds to the Reader commands. The
memory remains in the Asleep state until a valid
Talk command is received or the persistence
mode limit time has run out.
– TALK: XRA00, matching data sent by the
Reader, returns to the Awake state where it responds to commands from the Reader.
– KILL: XRA00, matching the entire ID Code, 16
bit CRC and the 8 bit Kill Code sent by the
Reader, no longer responds to Reader queries.
– ERASEID: The EraseID command is used to
erase the entire memory array.
– PROGRAMID: XRA00 programming is accomplished 16 bits at a time. Programming is allowed only when the XRA00 is not locked.
– VERIFYID: The VerifyID command is used to
verify that all memory data bits have been programmed correctly.
Figure 3. Die Floor Plan
(GND) AC0
ai10742
5/40
XRA00
DATA TRANSFER
Input Data Transfer from the Reader to the
XRA00 (Request Frame)
The RF Interface and Voltage Multiplier convert
the RF energy into the DC power required for the
XRA00 to operate. It provides modulation information to the ASK demodulator which discriminates
between High and Low digital levels and forwards
this discriminated signal to the State Logic for Data
Recovery (see Figure 4.).
Within the State Logic, the Data Recovery and
Timing Block recovers the data from the de-modulated signals and generates commands and control functions that coordinate all of the XRA00
operations. The State Logic interprets the Request
Frame, performs the required internal operations
and determines if a response is required. The
State Logic implements the State Diagram and
Communications Protocols.
The Reader-to-XRA00 link makes use of Amplitude Shift Keying (ASK) with a maximum modulation depth of 100% (see Figure 5.). Because of the
local UHF frequency regulation, the shape, depth
and rate of the modulation are variable within the
limits described in Table 2. The XRA00 adjusts its
timing over a range of modulation rates to lock to
Reader transmissions automatically.
Figure 4. ASK Modulation of the Received Wave
UHF Envelope
Low Level Interval
> 0%
< 50%
100%
< 50%
ai10743
Figure 5. ASK Pulse Modulation Parameters
Modulation
Ripple
0%
0.9 Modulation
0.5 Modulation
Modulation
tfwhm
0.1 Modulation
100%
tf
6/40
tr
Time
ai10744
XRA00
Symbol Transmission Format for Request
Frame
Modulation of negative pulse width (RF interruption period) is used for data transmission and synchronization to XRA00s. Four timings are
distinguished by their shortness. Their symbols
are as follows:
■
tfwhm0: encode binary data "0"
■
tfwhm1: encode binary data “1”
■
tfwhmBin: encode Bin synchroniZation pulse
■
ttrangap: encode Transaction Gap pulse
Each symbol is referenced to the Master Clock
Time Period, t0, which is defined by the Reader
during the Request Frame header modulation. t0 is
the bit duration period generated by the Reader.
Request Binary Data "0"
Data Modulation Timing, tfwhm0, for Reader-toXRA00 clocking when data = "0", is encoded by a
"narrow" 1/8t0 pulse width modulation. This timing
is also used during data synchronization at the begining of each Request Frame. tfwhm0 is illustrated
in Figure 6.
Request Binary Data "1"
Data Modulation Timing, tfwhm1, for Reader-toXRA00 clocking when data = "1", is encoded by a
"wide" 3/8t0 pulse width modulation. This timing is
also used for SOF (Start Of Frame) and EOF (End
Of Frame) symbols within the Request Frame.
tfwhm1 is illustrated in Figure 7.
Bin pulse and Bin Response Window
XRA00 Answer Frames are synchronized by the
Reader using Bin pulse modulation. The Bin pulse
is encoded by a 3/8t0 pulse width modulation.The
Bin pulse is also used to define the Bin Response
Window time slots during the inventory sequence
after a PINGID command is issued. The Bin Response Window is shown in Figure 8.
Transaction Gap
During communication with XRA00, each Request
Frame begins with a transaction gap, ttrangap, followed by a period of time, ttransetup, during which
the carrier frequency is unmodulated (See Figure
9. for an illustration and Table 2. for the value of
ttransetup). ttransetup precedes the Data Modulation
Window.
Power Up
If during communication with the Reader the carrier is turned off for a time exceeding tReset , XRA00
loses DC power. After XRA00 is powered up
again, a minimum time of ttransetup, during which
the carrier frequency is unmodulated, must precede the Data Modulation Window. (See Figure
10. for an illustration and Table 2. for the value of
ttransetup.)
Figure 6. Data Modulation Timing - “0”
t0
Clock Low
(Data '0')
tfwhm0 = 1/8t0
'0'
'0'
ai10745
Figure 7. Data Modulation Timing - “1”
t
0
Clock Low
(Data '1')
tfwhm1 = 3/8t0
'1'
'1'
ai10746
7/40
XRA00
Figure 8. Bin Response Window Timing
Bin Response Window
tfwhmBinRW = 8 x t0
Bin Pulse tfwhmBin = 3/8t0
ai10747
Figure 9. Transaction Gap Timing
Unmodulated carrier frequency
period ttransetup
Transaction Gap Pulse
ttrangap = 10/8t0
Previous
Transaction
Next Transaction
ai10748
Figure 10. Transaction after Power Up
Unmodulated carrier frequency
period ttransetup
treset
The carrier is off
8/40
ai10749
XRA00
Table 2. Request Modulation Pulse Parameters for North American Operation (−20 to 55°C)
Symbol
Description
Min
Max
Units
FC
UHF Carrier Frequency
900
930
MHz
t0
Master Clock Time Period for a single bit sent to the XRA00
12.5
16.6
µs
T0Tol
Master Clock Time Period Tolerance
-1
+1
%
1/t0
Request Frame Data Rate (1/t0)
60
80
Kbps
Tfwhm0
Pulse Modulation Width of Binary Data 0 at 50% Level
1/8 * T0
µs
Tfwhm1
Pulse Modulation Width of Binary Data 1 at 50% Level
3/8 * T0
µs
TfwhmBin
Pulse Modulation Width of Bin Pulse at 50% Level
3/8 * T0
µs
Ttrangap
Pulse Modulation Width of Transaction Gap at 50% Level
10/8 * T0
µs
TfwhmBinRW
Bin Response Window at 50% Level
Ttransetup
Delay between Transaction Gap and Data Modulation Windows
Ttranhold
Delay before the next Transaction Gap
tf
4*T0
8*T0
64
2.5*T0
µs
µs
2000
µs
Pulse Modulation Fall Time (90% to 10% level)
300
ns
tr
Pulse Modulation Rise Time (10% to 90% level)
300
ns
Ripple
Ripple
10
%
MOD
Pulse Modulation Depth
100
%
tCoast
Delay between Request EOF and the next Transaction Gap
20
ms
tReset
RF Off time to Power down a XRA00
80
200
µs
9/40
XRA00
Table 3. Request Modulation Pulse Parameters for European Operation (−20 to 55°C)
Symbol
Description
Min
Max
Units
FC
UHF Carrier Frequency
860
870
MHz
t0
Master Clock Time Period for a single bit sent to the XRA00
40
66,67
µs
t0Tol
Master Clock Time Period Tolerance
-1
+1
%
1/t0
Request Frame Data Rate (1/T0)
15
25
Kbps
tfwhm0
Pulse Modulation Width of Binary Data 0 at 50% Level
1/8 * T0
µs
tfwhm1
Pulse Modulation Width of Binary Data 1 at 50% Level
3/8 * T0
µs
tfwhmBin
Pulse Modulation Width of Bin Pulse at 50% Level
3/8 * T0
µs
ttrangap
Pulse Modulation Width of Transaction Gap at 50% Level
10/8 * T0
µs
tfwhmBinRW
Bin Response Window at 50% Level
ttransetup
Delay between Transaction Gap and Data Modulation Windows
ttranhold
Delay before the next Transaction Gap
tf
4*T0
8*T0
64
2.5*T0
µs
µs
2000
µs
Pulse Modulation Fall Time (90% to 10% level)
300
ns
tr
Pulse Modulation Rise Time (10% to 90% level)
300
ns
Ripple
Ripple
10
%
MOD
Pulse Modulation Depth
60
%
tCoast
Delay between Request EOF and the next Transaction Gap
20
ms
TReset
RF Off time to Power down a XRA00
40
200
µs
Note: The data shown in Table 3. is Preliminary Data. It is subject to change without previous notice.
Request Frame Format
Readers communicate with the XRA00 using two
types of modulation: Data modulation and Bin
modulation.
Data modulation is used to transmit data from the
Reader to the XRA00.
Bin modulation is used to synchronize XRA00 answers and define time slot intervals while running
the XRA00 anti-collision algorithm after a PINGID
command.
All transactions begin with a transaction gap pulse,
ttrangap, followed by a period of time at least equal
to ttransetup that precedes the Data modulation window as described in Figure 11.
During the Data modulation, the Reader provides
a master clock signal to XRA00 devices located in
its neighborhood. The time between clock pulses,
t0, determines the Reader-to-XRA00 data rate.
The XRA00 devices are synchronized to the
Reader on the negative-going edge of the low level interval of the RF envelope. There is a proportional relationship between this fundamental
frequency and all subsequent signaling.
10/40
The encoding used for the binary data from the
Reader to the XRA00 is the pulse width modulation of the low level pulse as shown in Figure 12.
Logical 0 is defined as a modulation whose width
is 1/8 of the master clock interval (Figure 6.), t0.
Logical 1 is encoded as a modulation whose width
is 3/8 of the master clock interval (Figure 7.), t0.
After the Data modulation windows in which the
Reader generates the XRA00 command, the
Reader generates Bin pulses to define the time
slots used by the XRA00 to answer. During the
first interval, after the Data modulation EOF, the
XRA00 sets up for answers. The XRA00 uses one
out of two Bin modulation schemes depending on
the Reader command.
For SCROLL commands, the Reader generates 1
Bin pulse used for synchronization, followed by the
XRA00 answer.
For PING commands, the Reader generates 8 BIN
pulses to define 8 BIN response windows. These
8 BIN response windows are used to delineate
XRA00 answers during a PINGID command.
A BIN interval is defined by a BIN pulse with a
width of tfwhmBin = 3/8t0, followed by a BIN response window delay of tfwhmBinRW = 8T0.
XRA00
At the end of a complete transaction, a minimun
delay of ttranhold = 2.5t0 (but that cannot exceed
tcoast) is required before the XRA00 is ready to receive the next Transaction Gap.
Figure 11. Reader to XRA00 Modulation Overview (Request Frame)
Bin Pulse
EOF
ttrangap or
Carrier on
Ping Command
(Bin Modulation)
EOF
Scrolll Command
(Carrier Wave after
Data Modulation)
Bin Pulse
Data Modulation Window
(Variable Length)
ttransetup
Tag Response Window
(Two Reader Modulation Option)
Tag Setup
Window (8 x t0)
ai10750
Figure 12. Data Modulation Window
t0
0
0
0
0
0
1
1
1
1
1
ai10751
Figure 13. Bin Modulations
EOF
Ping Command
tag
setup
ttranhold
8 x t0
Bin 0
Bin 1
Bin 2
Tag Response
Window
Scroll Command
Bin 3
Bin 4
ttranhold
Bin 5
Bin 6
ttrangap
Bin 7
ttrangap
tag
setup
ai10752
Figure 14. Bin Modulation Timing details
Bin Response Window
tfwhmBinRW = 8 x t0
Bin Pulse
tfwhmBin = 3/8 t0
Bin Response Window
tfwhmBinRW = 8 x t0
Bin Response Window
tfwhmBinRW = 8 x t0
ai10753
11/40
XRA00
Coast Interval
In order for the XRA00 to be able to detect the next
Transaction Gap, the Reader must start the next
transaction within tcoast (see Figure 15.). This re-
striction does not apply when the carrier has been
turned off long enough (at least for tReset) for DC
power to be removed from the XRA00 as the
XRA00 will re-synchronize at the next power-up.
Figure 15. Coast Interval
End of prior sequence
transaction gap or carrier on
Next sequence
Transaction gap
EOF
tCoast
ScrollID
Tag Response Windows
PingID
Bin Response Window
ai10754
Ping Reply Bin Collapse
The Reader may optionally shorten the Ping transaction time by shortening the Bin response window. The Reader may listen to a XRA00 reply
during the Bin response window for a minimum
time of 4t0 (= ttagscrollDell max), which is half the
standard BIN response window time. If no XRA00
response is detected, the Reader can generate
the next BIN pulse. This condition may be applied
to each of the 8 BIN intervals if the Reader detects
no reply from a XRA00. The middle Bin response
window shown in Figure 16. has been shortened
due to no XRA00 reply.
A Bin response window may not be collapsed
(shortened) if an answer from the XRA00 is detected. If the Reader collapses an occupied Bin interval, the reply from the occupying XRA00 may
overlap the collapsed Bin response window and
continue into the next one. The Reader may decode the overlapping reply as a collision in the
next Bin response window and will have to solve
the case.
Figure 16. Collapsed Ping Response
Bin Response Window
tfwhmBinRW = 8 x t0
Collapsed Bin
Response
Window = 4 x t0
Bin Response Window
tfwhmBinRW = 8 x t0
Tag answer
No Tag answer
Tag answer
Bin Pulse
tfwhmBin = 3/8 t0
12/40
ai10755
XRA00
Output Data Transfer from the XRA00 to the
Reader
Answer Binary Data Bits 0 and 1. The
backscattered answer from the XRA00 is modulated by
a selection of one out of two symbols per data bit
cell. The data bit cell period ttagbitcell is defined as
2 transitions for a binary data 0, and 4 transitions
for a binary data 1 as shown in Figure 17. The
nominal data rate for the XRA00 answer is synchronized to twice the Request data rate (defined
in Table 4.).
Under this encoding scheme, there are always
transitions in the middle of a data bit and the sequence of 0’s and 1’s remains unchanged when
the code is inverted as shown in Figure 19.
Figure 17. XRA00 Answer Binary Data Bit Cell Encoding
ttagbitcell = 1/2t0
ttagbitcell
Answer Data 1
Answer Data 0
ai10756
Answer Frame from the XRA00 to the Reader.
The XRA00 answers to Reader commands with a
backscatter modulation that follows the FSK bit
coding scheme as shown in Figure 17. This
scheme define two symbols which are binary data
0 and binary data 1, respectively.
After a Reader BIN pulse, the XRA00 waits for a
time that depends on the received command beore starting to generate the answer. The XRA00
answer consists of an 8 bit Preamble followed by
the data bits read from the non-volatile memory.
The preamble has a fixed value of 11111110 and
is sent as shown in Figure 18. The data bits are
sent lowest bit address first.
Figure 18. XRA00 Answer Preamble
EOF
ttagscrollDel
LSB MSB
READER
Bin Pulse
TAG
11111110
CRC data
Tag ID Code
Preamble
(8 bits)
16 bits
96 bits
ai10757
13/40
XRA00
Figure 19. Transmission of XRA00 Answers
100%
100%
ai10758
XRA00 Answer Bit Cell Variation. Durind the
Reader Request Frame command, the XRA00
synchronizes its internal PLL (Phase Lock Loop)
to the Master Clock Time Period, t0, generated by
the Reader. Due to the internal PLL drift in the
XRA00, the answer data bit cell period ttagbitcell
may vary by up to ±1/8t0.
Figure 20. XRA00 Answer Bit Cell Variation
ttagbitcell
−1/8t0
+1/8t0
Nominal Symbol at Start of Reply
Fast (−1/8t0) Symbol
Slow (+1/8t0) Symbol
ai10759
Table 4. XRA00 Backscattered Answer Modulation Parameters
Symbol
t0
Description
Min
Max
Units
Master Clock Time Period for a single bit sent to the XRA00
North American Operation
12.5
16.6
µs
Master Clock Time Period for a single bit sent to the XRA00
European Operation Preliminary Data
40
66.67
µs
ttagbitcell
XRA00 to Reader data bit cell period
1/2 x t0
µs
ttagbitcellTol
XRA00 to Reader data bit cell period Tolerance
(measured on 96+16+8 bits)
±1/8 x t0
µs
2 / t0
14/40
Answer Frame Data Rate (2/t0) for North American Operation
120
160
kbps
Answer Frame Data Rate (2/t0) for European Operation
Preliminary Data
30
50
kbps
XRA00
SCROLLID Answer Delay from Reader BIN pulse (nominal value
4.75 x t0)
4.68 x
t0
4.82 x
t0
µs
PINGID Answer Delay from Reader BIN Pulse (nominal value 4.25 x t0)
4.18 x
t0
4.32 x
t0
µs
ttagscrollRep
XRA00 SCROLL answer duration (96+16+8 bits, nominal value
120 x t0/2)
108 x
t0/2
132 x
t0/2
µs
terase
Erasing time
30
ms
tpgm
Programming time
30
ms
tKill
Kill time
30
ms
ttagscrollDel
15/40
XRA00
Scroll Answer. The duration of a ScrollID answer, ttagscrollRep, is illustrated in Figure 21.
The time required from the BIN pulse to the start of
a ScrollID or VerifyID answer, ttagscrollDel, is illustrated in Figure 22.
Figure 21. XRA00 Scroll Answer Duration
Bin Pulse
READER
ttagscrollRep
TAG
ai10760
Figure 22. ScrollID Answer Delay
Bin Pulse
READER
ttagscrollDel
TAG
ai10761
PingID Answer Delay. The time required from a
BIN pulse to the start of a PingID answer, ttagpingDel, is illustrated in Figure 23.
Figure 23. PingID Answer Delay
Bin Pulse
READER
ttagpingDel
TAG
ai10762
16/40
XRA00
er. Figure 24. shows XRA00 devices that present
the same backscatter modulation intensity and are
communicating simultaneously. Differences in
backscatter modulation intensity can also be used
to help detect contention.
Contention Detection
Contention detection is essential for most anti-collision algorithms. When two XRA00 devices have
the same clock rate and differ by only one bit, the
resulting difference in backscatter modulation
waveform should be readily detected by the Read-
Figure 24. Contention of Two XRA00 Devices with the Same Clock Rate and a 1-Bit Difference
100%
0
1
0
1
1
0
0
0/1
Bit contention example
ai10763
17/40
XRA00
MEMORY MAPPING
The XRA00 is divided into 8 blocks of 16 bits. The
device is read bit by bit and written to on a block by
block basis (16 bits at a time). The XRA00 memory
map is shown in Figure 25.
In the XRA00, the first block is used to store the
CRC value as defined in the ePC specification.
The next 6 blocks are used to store the 96-bit ePC
code that is used during the inventory sequence.
The last block is divided into two 8-bit areas, one
that contains the Kill Code and the other that contains the Lock Code used to protect the memory
data contents.
Figure 25. XRA00 Memory Map
Row
Address
15
0
EPC mapping
0
00D
Write Lockable User Area
CRC
1
16D
Write Lockable User Area
EPC Data
2
32D
Write Lockable User Area
EPC Data
3
48D
Write Lockable User Area
EPC Data
4
64D
Write Lockable User Area
EPC Data
5
80D
Write Lockable User Area
EPC Data
6
96D
Write Lockable User Area
EPC Data
7
112D
Lock Code
Kill Code
ai10764
Note: 1. ST may write part of the ePC code.
USER mode
After programming the ePC information, the
XRA00 can be locked. Once locked, the XRA00
18/40
answers to anti-collision and scroll commands
only. The ERASEID, PROGRAMID and VERIFYID commands are de-activated.
XRA00
COMMAND-REPLY
System communications follow a two-phase command-reply pattern where the Reader initiates the
transaction (Reader Talks First, RTF). In the first
phase, the Reader provides power to one or more
passive XRA00 device(s) with continuous wave
RF energy. The XRA00 device(s) power(s) up in
the "Awake" state, where it is/they are ready to
process commands. The Reader transmits amplitude-modulated information to the field using the
Reader-to-XRA00 encoding scheme described in
the Input Data Transfer from the Reader to the
XRA00 (Request Frame) paragraph. On completion of the transmission, the Reader ceases the
modulation and continues to apply the RF energy
to power the XRA00 device(s) during the reply
phase. The XRA00 device(s) communicate(s) with
the Reader via backscatter modulation during this
period, with the bit encoding scheme described in
the Answer Frame from the XRA00 to the Reader
paragraph.
Basic commands are designed to limit the amount
of state information the XRA00 device(s) have/has
to store between transactions. XRA00 devices on
the margin of the RF field are powered unreliably
and therefore cannot maintain a library of previous
transactions with the Reader. Consequently, the
basic command format centers on the notion of using "atomic" transactions with the XRA00 field.
This means that enough information is encased in
each command for XRA00 devices to respond appropriately without having to refer to previous
transactions.
XRA00 State Diagram
In the state diagram shown in Figure 26., the Power Up state is entered from any other state when
power is first applied, or when power is no longer
sufficient for the XRA00 to operate normally as described in Figure 10.
Power Up State. The XRA00 enters the power
up state on application of power, or when power
falls below the level required to operate the XRA00
internal logic. When power becomes acceptable
for operation, the XRA00 moves to the Awake
state.
Awake State. In the Awake state, the XRA00 interprets commands. It reacts to the Reader Request Frame and parameters and switches to the
appropriate state. The Awake State is entered
from the Power Up State but can also be entered
from the Asleep State on receipt of a valid Talk
Command.
Reply State. The XRA00 switches to the Reply
state when, after receiving a valid Request Frame,
it has to generate a response. On completion of
the Answer Frame, the XRA00 returns to the
Awake State.
Asleep State. The XRA00 switches from the
Awake state to the Asleep state on receipt of the
Quiet Command. In the Asleep state, the XRA00
will only respond to the Talk command. Other
commands are ignored.
If power is removed from the XRA00, the device
enters the Persistence mode which allows it to
switch back to the Asleep state when the device is
powered up again.
Dead State. The XRA00 enters the Dead state on
receipt of a valid Kill command with the correct Destruct Code sequence. In the Dead State the
XRA00 is Erased and does not provide valid ePC
data to the Reader.
19/40
XRA00
Figure 26. XRA00 State Diagram
Power-Up
Power Loss
Power Not OK
Power Up
Asleep,
Persistence mode
Power OK
Invalid
Command
ScrollAllID, ScrollID,
VerifyID(1) or PingID
Command
Reply
Quiet Command
Awake
Asleep
Talk Command
Reply complete
Programming
Commands
Program
Programming
Cycle
Completed
Kill Command
Dead
ai10765
20/40
XRA00
GENERAL COMMAND FORMAT
The XRA00 is expected to have limited oscillator
(PLL) stability. In the Request Frame format, the
Reader provides a serie of pulses to synchronize
the XRA00’s internal oscillator at the beginning of
each transaction. Answer Frames from the XRA00
are structured such that the Reader can interpret
the information transmitted at whatever clock rate
the XRA00 is able to provide. This scheme is similar in concept to auto-synchronization schemes
used in magnetic card or barcode Readers.
Two classes of Request Frames are provided:
■
Basic Commands: they provide XRA00
identification, sorting, inventory, etc. when
XRA00s are placed on goods in the supply
chain.
■
Programing Commands: they support XRA00
data initialization and programming by the final
tag user prior to the entry of the tagged items
in the supply chain.
21/40
XRA00
READER COMMAND STRUCTURE - (REQUEST FRAME COMMAND FORMAT)
The format of a basic command from the Reader
to the XRA00 is composed of 7 fields and 5 pieces
of parity information as shown below:
[SPINUP][SOF][CMD][P1][PTR][P2][LEN][P3]
[VALUE][P4][P5][EOF]
the LSB is transmitted first. The field definitions
are given in Table 5.
Programming commands have the same format
as basic commands (see Table 5.), except for a
few additional pulses (see Figure 34.) for an example of a programming command).
The Reader transmits the SPINUP field first, and
the EOF field is transmitted last. Within each field,
Table 5. Request Frame Command Field Definitions
Command
Field
Number
of bits
Field Description
[SPINUP]
20
Every Basic command is prefixed by a series of logical zeros (‘0’) for XRA00 timing. The
synchronization circuitry on the XRA00 uses this part of the message to establish its onboard
timing for reading/decoding messages and clocking subsequent replies to the Reader.
[SOF]
1
Start of Frame indicator. A logical one (‘1’)
[CMD]
8
8-bit field that specifies the command being sent to the XRA00 devices. (See Basic
Command Encoding below.) With 8 bits there could be up to 256 commands. The XRA00
command set only has six commands, the remaining address space is reserved.
[P1]
1
Odd Parity of the [CMD] field data.
[PTR]
8
8-bits - Pointer to a location (or bit index) in the XRA00 address range. The bit index starts at
the LSB and works up. [PTR] is the starting point for XRA00 devices to attempt a match with
data specified in the [VALUE] field. (Defined below.) The [PTR] field ranges from 0 to 255.
[P2]
1
Odd Parity of the [PTR] field data.
[LEN]
8
8-bits - Equal to the length of the data being sent in the [VALUE] field. (Defined below). The
[LEN] Field is always greater than zero.
[P3]
1
Odd Parity of the [LEN] field data.
[VALUE]
Variable
1 to 96 bits of data for XRA00 devices. In PingID, ScrollID, Quiet, or Kill commands, this is the
data that the XRA00 will attempt to match against its own address. The first bit received by
the XRA00 in the [VALUE] field will be compared to the XRA00 memory at the location
contained in the [PTR] field.
[P4]
1
Odd Parity of the [VALUE] field data.
[P5]
1
Odd Parity of all of the Parity fields.
[EOF]
1
End of Frame indicator. A logical one (‘1’).
22/40
XRA00
Command Encoding
For encoding the two sets of commands, Basic
and Programming, are also distinguished. Table 6.
shows how Basic Commands are encoded while
Table 7. shows the encoding of Programming
Commands.
Table 6. Basic Command Encoding
8-Bit Pattern
Hex
MSB <- LSB
8-Bit Pattern
Binary
MSB <- LSB
Reply from XRA00
SCROLLID
0x01
0000 0001b
“ScrollID Reply”
QUIET
0x02
0000 0010b
None
KILL
0x04
0000 0100b
None
PINGID
0x08
0000 1000b
“PingID Reply”
TALK
0x10
0001 0000b
None
SCROLLALLID
0x34
0011 0100b
“ScrollID Reply”
Basic Commands
[CMD]
Table 7. Programming Command Encoding
8-Bit Pattern
Hex
MSB <- LSB
8-Bit Pattern
Binary
MSB <- LSB
Reply from XRA00
ERASEID
0x32
0011 0010b
None
PROGRAMID
0x31
0011 0001b
None
VERIFYID
0x38
0011 1000b
“ScrollID Reply”
Programming Commands
[CMD]
23/40
XRA00
BASIC COMMANDS - OVERVIEW
The XRA00 provides six Basic commands, described in the following paragraphs.
specific XRA00 devices or test for the presence of
specific groups of XRA00 devices in the field. Data
sent by the XRA00 has a fixed length.
ScrollID
The ScrollID command is a Basic command that
gives rise to a response from the XRA00.
When the ScrollID command is issued, the XRA00
responds if the data sent by the Reader in the
[VALUE] field matches the XRA00's internal memory starting at the location specified by the [PTR]
field. Data in the [VALUE] field is compared to the
XRA00 memory, from the lowest to the highest address. Only XRA00 devices that match all of the
bits in the [VALUE] field reply to the Reader.
XRA00 devices that fail the match or fail a parity
test on any of the parity bits do not modulate.
The XRA00 devices that match the data sent by
the Reader reply by sending back an 8-bit preamble, a 16-bit CRC for error checking followed by
the entire 96-bit ePC code.
■
Any unlocked XRA00 seeing the command
will reply by sending back an 8-bit preamble,
16-bit CRC and its entire 96-bit ePC code,
plus the Kill code and Lock code location bits.
■
Any locked XRA00 seeing the command will
reply by sending back an 8-bit preamble, 16bit CRC and its entire 96-bit ePC code.
Data sent by the Reader to the XRA00 may be of
variable length. ScrollID can be used to look for
Example of a ScrollID Command . A Reader issues a command containing the following data:
[CMD] =
00000001b
(ScrollID)
(0x07)
[PTR] =
00000111b
(0x09)
[LEN] =
00001001b
(0x2D)
[VALUE] = 000101101b
XRA00 devices will attempt to check 9 bits of their
address data, starting at bit 7, against the data
specified in the [VALUE] field. XRA00 devices
whose data matches respond with a ScrollID Reply.
Table 8. shows the case of three XRA00 devices.
XRA00 1 and XRA00 3 respond to the command
but XRA00 2 does not. Underlined bits in XRA00
memory are compared with the [VALUE] data.
Here, bits 7 through 15 are compared.
The XRA00 devices start by modulating the lowest
memory address data bit onward up to the highest
memory address data bit. This means that in Table
8., modulation is from right to left.
Table 8. Example of a ScrollID Operation
XRA00 ID Code/Bit Number
Towards Highest
Address Bit
XRA00 responds to ScrollID command
Lowest Address Bit
Bit Number
...321098765432109876543210
-
XRA00 1 ID
...010001000001011011101010b
YES
XRA00 2 ID
...100111100001001010010010b
NO (bit 10 fails to match)
XRA00 3 ID
...101101010001011011110111b
YES
24/40
XRA00
ScrollID Answer Frame Description
The XRA00 devices that respond to a ScrollID
command reply by modulating an eight bit preamble (11111110) followed by a 16-bit CRC and the
entire XRA00 96-bit ePC code as shown in Figure
27. The XRA00 devices start by modulating from
the lowest to the highest memory address. The
XRA00 ScrollID Answer Frame structure is given
in Figure 27. The 16-bit CRC data contained in the
ScrollID Answer Frame is calculated accordingly
and stored into the XRA00 memory during the
XRA00 programming process.
Figure 27. ScrollID Answer Frame Structure
11111110 1110111111000001 110110000011011000101010000011101...10000011001011101001100111110000111100011101
Preamble
(8 bits)
CRC Data
(16 bits)
Tag ID Code
(96 bits)
XRA00 address 00h
XRA00 address 6Fh
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ScrollAllID
The ScrollAllID command is a Basic command that
gives rise to a response from the XRA00.
When this command is sent, the [VALUE], [PTR]
and [LEN] fields are ignored by the XRA00. This
command is similar to the ScrollID command described above, but for the discrimination.
■
Any unlocked XRA00 seeing the command
will reply by sending back an 8-bit preamble,
16-bit CRC and its entire 96-bit ePC code, as
well as the Kill code and Lock code location
bits.
■
Any locked XRA00 seeing the command will
reply by sending back an 8-bit preamble, 16bit CRC and its entire 96-bit ePC code.
The XRA00 devices start by modulating the lowest
memory address bit onward up to the highest
memory address bit.
Example of a ScrollAllID Command. A Reader
issues a command containing the following data:
[CMD] =
00110100b
(ScrollAllID)
(0x07)
[PTR] =
00000111b
(0x09)
[LEN] =
00001001b
[VALUE] = 000101101b
(0x2D)
The XRA00 devices will ignore all the field contents. Even though a data check takes place the
results of the check are ignored and all XRA00s
that receive the ScrollAllID command respond with
a ScrollID Reply.
In Table 9., XRA00 devices 1, 2 and 3 respond to
the command. Underlined bits in XRA00 memory
are compared with the [VALUE] data but the result
is not used.
Table 9. Example of a ScrollAllID Operation
XRA00 ID Code/Bit Number
Towards Highest
Address Bit
XRA00 respond to ScrollAllID command
Lowest Address Bit
Bit Number
...321098765432109876543210b
-
XRA00 1 ID
...010001000001011011101010b
YES
XRA00 2 ID
...100111100001001010010010b
YES (even though bit 10 fails to match)
XRA00 3 ID
...101101010001011011110111b
YES
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XRA00
ScrollAllID Answer Frame Description
XRA00 devices that respond to a ScrollAllID command reply by modulating an eight bit preamble
(7Fh) followed by a 16-bit CRC and the entire
XRA00 96-bit ePC code. The XRA00 devices start
by modulating the lowest memory address data bit
onward up to the highest memory address data bit.
The XRA00 ScrollAllID Answer Frame structure is
given in Figure 28. The 16-bit CRC data contained
in the ScrollAllID Answer Frame is calculated accordingly and stored into the XRA00 memory during the XRA00 programming process.
Figure 28. ScrollAllID Answer Frame Structure
11111110 1110111111000001 110110000011011000101010000011101...10000011001011101001100111110000111100011101
Preamble
(8 bits)
CRC Data
(16 bits)
Tag ID Code
(96 bits)
XRA00 address 00h
XRA00 address 6Fh
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Kill
The Kill command is a Basic command that gives
rise to an invalid response from the XRA00 to the
ePC Reader queries.
XRA00 devices whose data starting at the location
specified by the [PTR] field (must be cleared to ‘0’)
matches the entire [VALUE] field sent by the
Reader (that is, the 16-bit CRC, 96-bit ePC code
and an 8-bit Kill Code) are erased and do not provide valid ePC data to the Reader.
Data in the [VALUE] field is compared to XRA00
memory, from the lowest to the highest XRA00
memory address. XRA00 devices whose data do
not match or that fail a parity test on any of the parity bits enter the Persistence mode.
26/40
Killing a XRA00 can be done whether the
XRA00 is locked or not, assuming that the
correct Kill Code is issued during the
instruction
■
The Kill Code can be 00h
The time required to Kill a XRA00 is tKill (see Table
4., XRA00 Backscattered Answer Modulation Parameters for timings). It is anticipated that the Kill
command will require higher field strengths from
the Reader, and will therefore be a short-range operation.
The Reader to XRA00 Request Frame for a Kill
command is similar to the Request Frame for a
EraseID or ProgramID command.
■
XRA00
Figure 29. Kill Signaling
Prior sequence
transaction gap
or carrier off
64µs
Spin up
20 0's
tKill
Data
000000000000000000000 1
S Kill
O
F
P
3
t0
EOF
P Pointer
1=0
D
P Length
2 always
120D
P 16 bit CRC P P E
3 + 96 bit EPC 4 5 O
F
+ Kill code
16 bit CRC + 96 bit EPC + Kill code
0's
Power Off Interval
Between Rows
= 8t0 minimun
10000000
7 0's
PP E
45 O
F
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27/40
XRA00
PingID
The PingID command is a Basic command that
gives rise to a response from the XRA00.
When the command is sent, the XRA00 will respond if the data sent by the Reader in the [VALUE] field matches the data in the XRA00's internal
memory starting at the location specified by the
[PTR] field. Data in the [VALUE] field is compared
to the XRA00 memory, from the lowest to the highest memory address. XRA00 devices whose data
matches all of the bits in the [VALUE] field will reply to the Reader. XRA00 devices whose data
does not match or that fail a parity test on any of
the parity bits will not modulate.
The PingID command is used as part of a multiXRA00 anti-collision algorithm described in detail
hereafter.
XRA00 devices that match the data sent by the
Reader respond with 8 address bits, from a point
designated by two parameters supplied by the
Reader, in increasing address order.
Each XRA00 response is placed in one of 8 Bin
Response Windows delineated by BIN pulses sent
by the Reader.
Example of a PingID Command. A Reader issues a PingID command containing the following
data:
[CMD] =
00001000b
(PingID)
(0x07)
[PTR] =
00000111b
(0x09)
[LEN] =
00001001b
(0x2D)
[VALUE] = 000101101b
The XRA00 devices will attempt to check 9 bits of
their address data, starting at bit 7 against the data
specified in the [VALUE] field.
In the example shown in Table 10., the underlined
bits in the XRA00 ID code are compared with the
[VALUE] data sent by the Reader. Bits shown in
Italic are modulated and returned to the Reader
during one of the Bin Response Windows. The
lowest 3 bits of the response determine the response bin number.
Table 10. Example of PingID Operation
XRA00 responds to
PingID command
XRA00 ID Code/Bit Position
Towards Highest
Address Bit
Bin for
response
Lowest Address Bit
8-Bit
response
MSB
LSB
Bit Number
...321098765432109876543210
-
-
-
XRA00 1 ID
...010001000001011011101010b
YES
Bin 4 (100b)
01000100b
XRA00 2 ID
...100111100001001010010010b
NO
(bit 10 does not match)
-
-
XRA00 3 ID
...111101010001011011110110b
YES
Bin 5 (101b)
11110101b
XRA00 4 ID
...101100000001011011110111b
YES
Bin 0 (000b)
10110000b
Figure 30. PingID Answer Frame Structure for XRA00 3
Bin 5
(101)
Bin 6
(110)
10101111 (pattern reflects order of transmission)
Tag Data (8 bits)
Lowest XRA00
address
PingID Answer Frame
The PingID command is used in the anti-collision
28/40
Highest XRA00
address
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algorithm. This command requires that the XRA00
devices that match the data sent by the Reader reply with 8 modulated data bits in one of 8 Bin Re-
XRA00
XRA00 devices where the 3 bits are equal to '111'
respond in the eighth Bin Response Window.
These Bin Response Window are also called
"bins" and numbered from 0 through to 7 as shown
in Figure 31.
As described in the Ping Reply Bin Collapse paragraph, the Reader may shorten a BIn Response
Window if no tag answer is detected.
sponse Windows delineated by BIN pulses from
the Reader after a Setup time.
The 3 bits of XRA00 memory that come immediately after the matched data determine the particular Bin Response Window for an XRA00 reply.
XRA00 devices where these 3 bits are equal to
'000' respond in the first Bin Response Window,
XRA00 devices where the 3 bits are equal to '001'
reply in the second Bin Response Window...
Figure 31. PingID Answer Response Period - Reader Modulations Define Response Bins
Bin 0
(000)
Setup
EOF from CMD
Bin 1
(001)
Bin 2
(010)
Bin 3
(011)
Bin 4
(100)
Bin 5
(101)
Bin 6
(110)
Bin 7
(111)
BIN pulses
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Quiet
XRA00 devices that match the data sent by the
Reader enter the Asleep state where they no longer respond to Reader commands. They remain in
the Asleep state until they receive the appropriate
Talk command or after the Persistance mode time
limit is exceeded (even if power has been removed
from the XRA00).
Example of a Quiet Command. A Reader issues a Quiet command containing the following
data:
[CMD] =
00000010b
(Quiet)
(x07)
[PTR] =
00000111b
(0x09)
[LEN] =
00001001b
[VALUE] = 000101101b
(0x2D)
XRA00 devices will attempt to check 9 bits of their
address data, starting from bit 7, against the data
specified in the [VALUE] field. XRA00 devices
whose data matches enter the Asleep state and
remain in this state.
Once in the Asleep state the XRA00 devices will
fail to respond to any command until they receive
a Talk command or the Persistence mode limit
time is exceeded.
The XRA00 devices do not return any response to
the Quiet command.
In the example illustrated in Table 11., the underlined XRA00 memory bits are compared with the
[VALUE] data sent by the Reader.
After issuing the Quiet command, the Reader must
transmit seven 0’s after the EOF for the XRA00 to
execute the Quiet command. Once the seven 0’s
have been sent, the Reader is allowed to start a
new transaction.
Table 11. Example of a Quiet Operation
XRA00 ID Code/Bit Position
Towards Highest Address Bit
XRA00 execute Quiet command
and become inactive
Lowest Address Bit
Bit Number
...321098765432109876543210
-
XRA00 1 ID
...010001000001011011101010b
YES
XRA00 2 ID
...100111100001001010010010b
NO (bit 10 does not match)
XRA00 3 ID
...101101010001011011110110b
YES
XRA00 4 ID
...101100000001011011111011b
YES
29/40
XRA00
Figure 32. Example of a Quiet Request Frame Signaling
EOF
Transaction Gap
7t0
Quiet, Talk
Commands
Next
Transaction
1
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Talk
[VALUE] = 000101101b
XRA00 devices that match the data sent by the
Reader return to the Awake state, where they will
respond to commands from the Reader.
XRA00 devices inactivated by the Quiet command
can be reactivated by the Talk command.
The Talk command follows the same rules as the
Quiet, PingID and ScrollID commands for the selection of the XRA00 devices. An individual XRA00
or a group of XRA00 devices can be brought out of
the Asleep state, as required.
The XRA00 devices will attempt to check 9 bits of
their address data, starting from bit 7, against the
data specified in the [VALUE] field. The XRA00
devices with matching data revert from the Asleep
to the Awake state thus becoming responsive to all
subsequent Reader commands until a new Quiet
command is received.
The XRA00 devices do not return any response to
the Talk command.
In the example illustrated in Table 12., the underlined XRA00 memory bits are compared with the
[VALUE] data sent by the Reader.
After issuing the Talk command the Reader must
transmit seven 0’s after the EOF for the XRA00 to
execute the Talk Command. Once the seven 0’s
have been sent, the Reader must immediately issue a transaction gap.
Example Talk Command. A Reader issues a
Talk command containing the following data:
[CMD] =
00110010b
(Talk)
(0x07)
[PTR] =
00000111b
(0x09)
[LEN] =
00001001b
(0x2D)
Table 12. Example of a Talk Operation
XRA00 ID Code/Bit Position
Towards Highest
Address Bit
XRA00 executes the Talk command and enters the
Awake state
Lowest Address Bit
Bit Number
...321098765432109876543210
-
XRA00 1 ID
...010001000001011011101010b
YES
XRA00 2 ID
...100111100001001010010010b
NO (bit 10 does not match)
XRA00 3 ID
...101101010001011011110110b
YES
XRA00 4 ID
...101100000001011011110111b
YES
Figure 33. Example of aTalk Request Frame Signaling
EOF
Transaction Gap
7t0
Quiet, Talk
Commands
Next
Transaction
1
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30/40
XRA00
PROGRAMMING COMMANDS - OVERVIEW
Programming commands use the same command
structure and field definitions as the Basic commands, but are issued only by an XRA00 programmer.
An XRA00 programmer may be similar to a Reader, except that it can execute Programming commands in addition to Basic commands.
Programming commands are used to program the
contents of the XRA00 non-volatille memory, and
to verify these contents before locking them. All
Programming commands are disabled once the
manufacturer has locked the XRA00 data contents. The programming range is approximately
25% of the maximum read range. The programming distance depends on the tag antenna design,
tag materials, programmer antenna design, RF
power level and system configuration.
VerifyID
The VerifyID command is used to examine the
contents of a memory block as part of a programming cycle in order to allow the manufacturer programmer to verify that the entire memory block
has been programmed correctly into the XRA00.
XRA00 devices that have been LOCKED will not
answer to the VerifyID command. The VerifyID
command addresses all bits in the XRA00 memory
that are transmited to the programmer in the same
Answer Frame format as the ScrollAllID Reply.
EraseID
The EraseID command resets all bits in the
XRA00 to the value "0". This command is a bulk
erase of the entire memory array. The EraseID operation is normally executed prior to the ProgramID command. The EraseID command is not
executed on XRA00 devices that have been
LOCKED. The data sent by the Programmer in the
[PTR] and [VAL] fields are not used by the XRA00
and should be set to "0". The [LEN] field should be
set to the value “1”, and the [VAL] field should contain a single "0". Upon receipt of a valid EraseID
command, the XRA00 executes the appropriate
internal timing sequences required to erase the
memory.
See Figure 34. for the EraseID command signaling
sheme.
ProgramID
The XRA00 is programmed 16 bits at a time. Programming is only allowed if the XRA00 is not
locked. The data is sent to the XRA00 using the
ProgramID command. The [PTR] field contains the
memory row address to be programmed and the
[VAL] field contains the 16 bits of data to be programmed. The [PTR] field value must be set as
specified in Table 13.
See Figure 34. for the ProgramID command signaling sheme.
The [LEN] field must be set to the value 16
(00010000b), indicating that 16 bits are programmed.
Upon receipt of a valid ProgramID command, the
XRA00 executes the appropriate internal timing
sequences required to program the memory.
Table 13. Programming Row Selection
[PTR] Value
[PTR] Value
MSB LSB
Row to be Programmed
00D
00000000b
row 0, bits 0-15
16D
00010000b
row 1, bits 16-31
32D
00100000b
row 2, bits 32-47
48D
00110000b
row 3, bits 48-63
64D
01000000b
row 4, bits 64-79
80D
01010000b
row 5, bits 80-95
96D
01100000b
row 6, bits 96-111
112D
01110000b
row 7, bits 112-127
31/40
XRA00
grammed with the value A5h, as shown in Table
14. and Table 15.
If a value different from A5h is programmed in the
8 upper bits of the row 7, the tag in NOT LOCKED,
and the XRA00 will return this value in response to
any ScrollID, ScrollAllID or Verify command.
Lock Function
The Lock function is implemented by programming
a specific value into the lock bits of the XRA00, using the ProgramID command. In order to lock the
XRA00, the 8 upper bits of the row 7 must be proTable 14. Row 7 of an Unlocked or Erased Memory
Row 7
Lock Bit
Kill Code
bit8bit 1
bit8bit1
bit
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
Value
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 15. Row 7 of a Locked Memory (Showing Lock Code A5h)
Row 7
Lock Bit
Kill Code
bit8bit 1
bit8bit1
bit
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
Value
1
0
1
0
0
1
0
1
0
0
0
0
0
0
0
0
EraseID and ProgramID Timing
■
The time required to erase or program a XRA00 is
terase and tpgm, respectively. See Table 4., XRA00
Backscattered Answer Modulation Parameters for
values.
The Reader to XRA00 Request Frame is much like
the Basic Command frame. The differences between the two are listed below:
■
The Programmer must send 0's after the
[EOF] for the duration of the program or erase
time, tpgm or terase.
■
■
The ProgramID and EraseID operations are
terminated by a "1" at the end of terase or tpgm.
The Programmer must transmit seven 0's after
the terminating "1" to allow the XRA00 to
perform an orderly shutdown of the erase/
program sequence.
Transmission of subsequent programming
commands must be preceded by an XRA00
carrier off interval of at least 8 x t0.
Figure 34. EraseID and ProgramID Signaling
Prior sequence
transaction gap
or carrier off
64µs
Spin up
20 0's
000000000000000000000 1
terase or tpgm
Variable Data
S
P
O Command 1 Pointer
F
P
2
P
Length 3
always 16
t0
EOF
16 data bits
Value
PP E
45 O
F
0's
Power Off Interval
Between Rows
= 8t0 minimun
10000000
7 0's
variable
number
of bits
P
3
PP E
45 O
F
variable number of bits
ProgramID, EraseID Commands
32/40
ai10772
XRA00
ANTI-COLLISION ALGORITHM
The PingID command divides a population of
XRA00 devices into eight sub-populations based
on their ID code by binning XRA00 responses into
eight separate time slices, or Bin Response Windows. This binning provides the basis for an anticollision algorithm that probes the binary ID code
three bits at a time. Individual XRA00 devices can
be isolated from large populations in the field of
the Reader by issuing multiple PingID commands
to the field, analyzing the responses and eventually issuing the appropriate ScrollID command.
Figure 35. is a binary tree representation of the
first four LSBs in the XRA00 address space. Although only the four first levels are shown, the binary tree structure applies to the entire XRA00 ID
code (96 bits for a Class-1b XRA00).
A PingID command with [PTR]=0, [LEN]=1 and
[VALUE]=0 will probe the right half of this tree (the
‘0’ branch) through the first four bits of the XRA00
memory.
Similarly, a PingID command with [PTR]=0,
[LEN]=1 and [VALUE]=1 will probe the left half of
this tree (the ‘1’ branch) through the first four bits
of the XRA00 memory.
For the PingID command with [PTR]=0, [LEN]=1
and [VALUE]=0, XRA00 devices whose LSBs are
0000b respond in bin 0, XRA00 devices whose
LSBs are 0010b respond in bin 1... and XRA00 devices whose LSBs are 1110b respond in bin 7.
Readers can look for backscatter modulation from
the XRA00 devices in each of the bins and learn
about the XRA00 population even if collisions
make reading the 8 bits of data sent by the XRA00
devices difficult.
The presence of backscatter in a given bin merely
indicates that one or more XRA00 device(s)
match(es) the query. The bin number tells the
Reader what the next three MSBs of the XRA00
addresses will be. The bin contents also indicate
the next 5 bits of the responding XRA00 devices.
Figure 35. First Four LSBs as a Binary Tree
UE
1
N=
PTR
VAL
=1
LE
=0
PTR
=0
LEN
=1
VAL
UE
=0
1
0
11
111
01
011
1111 0111 1011 0011
101
10
001
1101 0101 1001 0001
110
00
010
1110 0110 1010 0010
100
000
1100 0100 1000 0000
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Anti-Collision Example
Consider two XRA00 devices having their lowest
address programmed with 0111b and 1011b, respectively.
Query 1
[CMD] =
[PTR] =
[LEN] =
[VALUE]
00001000b(PingID)
00000000b(0x00)
00000001b(0x01)
= 1b(1)
This command probes the left half of the tree
shown in Figure 35. The [VALUE] field of 1, matches the first bit of both XRA00 devices in the exam-
ple (0111b and 1011b), so that they will both
respond.
During the reply interval, the XRA00 devices modulate the next 8 bits of their address data that
come just after the matched portion on the higher
address side. The bin in which they modulate is
determined by the three LSBs of the data they
modulate. At the Reader, backscatter modulation
is observed in bins 3 (011b) and 5 (101b) (as
shown in Figure 36.). Since multiple XRA00 devices can modulate in each of these bins, contention
may be observed but the Reader knows that there
are two distinct populations of XRA00 devices
present whose first four LSBs are 0111b and
1011b, respectively.
33/40
XRA00
Using this information, the Reader may issue a
second PingID command to explore the population of XRA00 devices in bin 3, reserving the
XRA00 devices detected in bin 5 for later analysis:
Query 2
[CMD] =
[PTR] =
[LEN] =
[VALUE]
00001000b(PingID)
00000000b(0)
00000100b(4)
= 0111b(7)
This command explores 3 bits farther into the tree
towards the highest memory location from the
memory address containing the bits 0111b. In Figure 37., the bold borders show the branches that
contain the XRA00 devices. The two branches
shown in the second half of the drawing contain
groups of XRA00 devices that match Query 2.
These are the same XRA00 devices that responded to the first query in bin 3.
In this new query, the XRA00 modulation during
the reply interval will take place in bins 1 (response
0010111b), 6 (response 1100111b) and 7 (response 1110111b) as shown in Figure 38. and in
bold in Figure 37. The Reader knows 7 address
bits of these XRA00 devices and at least 4 bits of
information concerning the other XRA00 branch
affected by Query 1 but reserved for later analysis.
Although it is not the fastest way to isolate and
identify XRA00 devices, the Reader may continue
with this method and use the PingID command to
follow a branch through the XRA00 ID space until
it has explored the entire XRA00 address and 16bit CRC of the XRA00 address.
The recommended way to perform an analysis of
a population of XRA00 devices is to take advantage of the Reader's ability to detect contention in
the reply intervals. The "divide by eight" feature of
the PingID command makes it possible to very
quickly reduce the number of XRA00 devices replying in each bin. Simulations with populations of
100 XRA00 devices show that with random addresses, an average of less than 4 PingID commands are needed to isolate one XRA00 device. If
only one XRA00 replies in a given bin, the Reader
can decode the 8 bits of information sent from the
XRA00 and issue a ScrollID command to that
XRA00 using the [PTR] [LEN] and [VALUE] data
that successfully isolated the XRA00.
Figure 36. Reader Modulations and XRA00 Backscatter During PingID Reply for Query 1
Reader
Bin
Modulation
000
001
010
011
100
101
110
111
Tag Backscatter
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XRA00
Figure 37. Query Tree for the Two PingID Sequence
Query 1
1
0
11
111
01
011
101
1111 0111 1011 0011
001
1110111
0110111
010
1110 0110 1010 0010
Query 2
010111
1010111
100
000
1100 0100 1000 0000
00111
100111
0010111
00
110
1101 0101 1001 0001
10111
110111
10
1100111
0100111
000111
1000111
0000111
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Figure 38. Reader Modulations and XRA00 Backscatter During PingID Reply for Query 2
Reader
Bin
Modulation
000
001
010
011
100
101
110
111
Tag Backscatter
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XRA00
ANTI-COLLISION FEATURES
Several features of this anti-collision approach deserve mention:
■
Each transaction with the XRA00 field is a selfcontained operation. A command - reply pair is
an atomic transaction requiring no knowledge
of previous events from a XRA00 for it to reply.
This feature greatly enhances robustness for
passive XRA00 devices in noisy environments
or at marginal RF power levels.
■
Related to this, the Reader maintains
information about the progress through the
binary tree. Branches that show XRA00
signals, but are not immediately explored may
be held in memory and later examined to
improve the overall throughput.
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■
Readers with widely varying capabilities can
make use of the same protocol.
– A sophisticated Reader that can perform
contention detection within a bin can
perform very rapid sorts of groups of
XRA00 devices. XRA00 devices can be
quickly isolated using a series of PingID
commands, and then read using the
ScrollID command.
– Simple Readers without the ability to
detect contention (for example, a Reader
with only an analogue filter to look for
"XRA00-like" modulation) can still sort and
identify XRA00 devices using only the
PingID command.
XRA00
XRA00 IMPEDANCE PARAMETERS
The XRA00 parameters are specified in Tables 16
and 17.
Table 16. XRA00 Parameters
Symbol
Description
Conditions
tSTG
Storage Temperature
VOP
Minimum Operating voltage on the
antenna
Min
Max
Unit
15
25
°C
23
months
Wafer
FC = 915MHz, T = 25°C, Regulated
Internal VDD = 1.65V
0.5
Vrms
–50(2)
+50(2)
V
–200(3)
+200(3)
V
–400(2)
+400(2)
V
–2500(3) +2500(3)
V
Machine Model
VESD
Electrostatic Discharge Voltage (1)
Human Body Model
Note: 1. Mil. Std. 883 - Method 3015.
2. VESD values for 6-inch wafers.
3. VESD values for 8-inch wafers.
Table 17. 6-inch Wafer XRA00 Impedance Parameters
Equivalent Serial Model for 6-inch wafers
(See Figure 39.)
Measurement conditions
T = +25°C, Regulated Internal VDD = 1.65V
Typical Value Characterized only.
Fc = 868MHz, Rs = 7.4Ω, Xs = −218Ω
Fc = 915MHz, Rs = 6.7Ω, Xs = −197.4Ω
Table 18. 8-inch Wafer XRA00 Impedance Parameters
Equivalent Serial Model for 8-inch wafers
(See Figure 39.)
Measurement conditions
T = +25°C, Regulated Internal VDD = 1.65V
Typical Value Characterized only.
Fc = 915MHz, Rs = 7Ω, Xs = −184Ω
Figure 39. XRA00 Input Impedance, Equivalent Serial Circuit
AC0
RS
Zeq
XS
AC1
Zeq = RS + jXS
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XRA00
PART NUMBERING
Table 19. Ordering Information Scheme
Example:
XRA00 -
W4I
/
XXX
Device Type
XRA00
Delivery Form
W4I = 180µm ± 15µm unsawn Inkless wafer
SBN18I = 180µm ± 15µm Bumped and Sawn Inkless Wafer
Customer Code
XXX = Customer Code, given by STMicroelectronics
Note: Initial delivery state: devices on wafers are shipped from the factory with the memory contents
cleared to all “0’s” (00h).
For a list of the available options, please see the current Memory Shortform Catalogue.
For further information on any aspect of this device, please contact your nearest ST Sales Office.
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XRA00
REVISION HISTORY
Table 20. Document Revision History
Date
Version
15-Dec-2004
0.1
21-Oct-2005
2
Revision Details
First Issue
VESD values for 8-inch wafers added to Table 16., XRA00 Parameters. Parallel model
removed. Table 18., 8-inch Wafer XRA00 Impedance Parameters added.
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XRA00
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