139037 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.8 — 11 November 2013
139038 18 of 48
NXP Semiconductors
SL3ICS1002/1202
UCODE G2XM and G2XL
13.3 Link timing
For the interrogator interacting with a UCODE G2X equipped tag population exact link and
response timing requirements must be fulfilled, which can be found in Section 17
, Ref. 1,
chapter 6.3.1.6.
13.3.1 Regeneration time
The regeneration time is the time required if a G2X is to demodulate the interrogator
signal, measured from the last falling edge of the last bit of the G2X response to the first
falling edge of the interrogator transmission. This time is referred to as T2 and can vary
between 3.0 Tpri and 20 Tpri. For a more detailed description refer to Section 17
, Ref. 1,
chapter 6.3.1.6.
13.3.2 Start-up time
For a detailed description refer to Section 17, Ref. 1, chapter 6.3.1.3.4.
13.3.3 Persistence time
An interrogator chooses one of four sessions and inventories tags within that session
(denoted S0, S1, S2, and S3). The interrogator and associated UCODE G2X population
operate in one and only one session for the duration of an inventory round (defined
above). For each session, a corresponding inventoried flag is maintained. Sessions allow
tags to keep track of their inventoried status separately for each of four possible
time-interleaved inventory processes, using an independent inventoried flag for each
process. Two or more interrogators can use sessions to independently inventory a
common UCODE G2X chip population.
A session flag indicates whether a G2X may respond to an interrogator. G2X chips
maintain a separate inventoried flag for each of four sessions; each flag has symmetric A
and B values. Within any given session, interrogators typically inventory tags from A to B
followed by a re-inventory of tags from B back to A (or vice versa).
Additionally, the G2X has implemented a selected flag, SL, which an interrogator may
assert or deassert using a Select command.
For a description of Inventoried flags S0 – S3 refer to Section 17
, Ref. 1 chapter 6.3.2.2
and for a description of the Selected flag refer to Section 17
, Ref. 1, chapter 6.3.2.3. For
tag flags and respective persistence time refer to Section 17
, Ref. 1, table 6.14.
13.4 Bit and byte ordering
The transmission order for all R=>T and T=>R communications respects the following
conventions:
• within each message, the most-significant word is transmitted first, and
• within each word, the most-significant bit (MSB) is transmitted first,
whereas one word is composed of 16 bits.
To represent memory addresses and mask lengths EBV-8 values are used. An extensible
bit vector (EBV) is a data structure with an extensible data range. For a more detailed
explanation refer to Section 17
, Ref. 1, Annex A.
