ATA559001-6DSY Atmel, ATA559001-6DSY Datasheet - Page 81

• Manufacturer Part Number: ATA559001-6DSY
• Description: RF Wireless Misc UHF (1k bit r/w anti-collision)
• Manufacturer: Atmel

Specifications of ATA559001-6DSY

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

13. Deterministic Arbitration and Group Selection
4817C–RFID–03/07
ATA5590 supports deterministic-based anticollision procedures as well as a group-selection
mechanism. After initializing the link, an arbitration procedure follows. During these procedures,
the link between the reader and tag is full duplex.
This means that the tag backscatters its internal (memory) value back to the reader, while the
reader transmits priority information to the tag. This priority information is used as a confirmation
from the reader to indicate the priority decision of the reader. The information is PIE. The refer-
ence length of PIE is transmitted by the reader during the return link header.
As opposed to Aloha-based anticollision routines (Aloha-based routines backscatter a stream
only if the slot number is equal to the internal (random) number), in deterministic-based routines,
the tag backscatters as long as the compare condition is true.
Therefore, it is possible for more than one tag to backscatter its information during one bit.
The deterministic-based anticollision routines are the same as for group-selection commands.
The difference is the effect on the register status1.
The differences between group and deterministic anticollision commands are
Deterministic anticollision procedures are mainly used to select one out of n tags. For such appli-
cations, ATA5590 supports several commands addressing different application scenarios. A
main feature of ATA5590 is that it does not need unique ID structures for arbitration because the
arbitration can also be based on random values.
This makes it possible to use this mechanism to program virgin tags, which are in a box, for
example, with unique identifiers.
The random value has a maximum size of 16 bits. After each deterministic access, the selected
tag is in a mute state. All the other tags calculate a new random number, and if the reader sends
either this command again or the repeat_arb command, the reader can fetch the next tag. Then
the 16-bit random number that was calculated by the tag which is now in the mute state, can be
used again. Therefore, this algorithm is not limited by the size of the random value.
• During group selection, the tag backscatters its value, but the reader is free to observe the
• Group selection supports a hierarchical mechanism
• Group-selection commands only affect the pre_select flag (set and reset mechanism).
• Deterministic anticollision commands work the same as group-selection commands. The
• Deterministic anticollision commands affect the ID flag (set). Deterministic anticollision
• If the tag receives a second anticollision command and ID was set before, the tag will be
• A reset of the status1 register flags is possible by a reset command.
communication. In any case, the reader is able to check if there is a tag which can be
addressed by this priority code.
reader is free to interpret the backscattered value.
supports only a set mechanism for ID and ID_s.
silent and ID_s will be set.
ATA5590
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