ATA559001-6DSY Atmel, ATA559001-6DSY Datasheet - Page 48

• 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

7.2
7.3
7.3.1
7.3.2
48
Return Link
Handover Timing
ATA5590
Forward Link to Return Link
Return Link to Forward Link
The return link depends on the command. After receiving a read command, it is based on:
If ATA5590 has received a program command, the reader has to send a continuous wave until
the tag backscatters a ready signal (sub-carrier), because ATA5590 supports an adaptive pro-
gramming algorithm to enable short-distance and long-distance programming routines. After
receiving this acknowledge signal, the reader starts transmitting the sequence as just described.
Anticollision, group-selection, and wake-up commands are based on different return link struc-
tures; only the headers are the same. The return links of the anticollision and group-selection
commands look the same as the forward links.
In the case of wake-up commands, the 8-bit status information is replaced by a 16-bit slot zone.
The mode of the return link is the synchronous communication mode; the reader transmits the
header sequence to adjust timings, and transmits notches to mark the boundaries of the link.
In synchronous operation mode, the reader is able to get the message in a loop by transmitting
a new header sequence instead of the EOT frame.
It is also possible to send only the CRC in a loop (adaptive CRC) by inserting an EOF symbol at
the position of the last data bit (LSB). The reader can also shorten the CRC zone.
As the handover mechanism from the forward link to the return link is synchronous, there is no
wait cycle between the link mechanisms. The forward link is closed by the EOT stream. Then the
tag expects the return link header for further control settings.
After the return link header is passed, the reader is free to stop the return link at any point by
sending the EOT sequence. If the adaptive CRC field is selected, the reader has to send the
EOT sequence as well.
The tag decodes the first clock tick of the return link after the EOT sequence (the symbol must
be closed) as the start of the forward header. The time between this first notch (forward header)
and the end of the EOT sequence is therefore limited by the RF regulation.
• Header section to define different timings and spectra
• Status byte
• Data section
• CRC section
• End of frame (EOT) section
4817C–RFID–03/07