XRA00SBN18I1GE STMicroelectronics, XRA00SBN18I1GE Datasheet - Page 19

• Manufacturer Part Number: XRA00SBN18I1GE
• Manufacturer: STMicroelectronics

Specifications of XRA00SBN18I1GE

• Lead Free Status / RoHS Status: Compliant

COMMAND-REPLY
System communications follow a two-phase com-
mand-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 ampli-
tude-modulated information to the field using the
Reader-to-XRA00 encoding scheme described in
the
XRA00 (Request Frame)
tion 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
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 us-
ing "atomic" transactions with the XRA00 field.
This means that enough information is encased in
each command for XRA00 devices to respond ap-
propriately without having to refer to previous
transactions.
Answer Frame from the XRA00 to the Reader
Input Data Transfer from the Reader to the
paragraph. On comple-
XRA00 State Diagram
In the state diagram shown in
er 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 de-
scribed in
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 in-
terprets commands. It reacts to the Reader Re-
quest Frame and parameters and switches to the
appropriate state. The Awake State is entered
from the
from the
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
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 De-
struct Code sequence. In the Dead State the
XRA00 is Erased and does not provide valid ePC
data to the Reader.
State.
Power Up State
Asleep State
Figure 10.
on receipt of a valid Talk
but can also be entered
Figure
26., the Pow-
XRA00
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