XRA00 Datasheet, PDF (13/40 Pages) STMicroelectronics – UHF, EPCglobal, Contactless Memory IC 96 bit ePC with Inventory and Kill Function

XRA00
Output Data Transfer from the XRA00 to the
Reader
Answer Binary Data Bits 0 and 1. The back-
scattered answer from the XRA00 is modulated by
a selection of one out of two symbols per data bit
cell. The data bit cell period t_tagbitcell 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 syn-
chronized 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 se-
quence 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
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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.
Figure 18. XRA00 Answer Preamble
After a Reader BIN pulse, the XRA00 waits for a
time that depends on the received command be-
ore 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.
READER
TAG
EOF
ttagscrollDel _{LSB MSB}
Bin Pulse
11111110
Preamble
(8 bits)
CRC data
16 bits
Tag ID Code
96 bits
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