ATA559001-DDT Atmel, ATA559001-DDT Datasheet - Page 89

• Manufacturer Part Number: ATA559001-DDT
• Description: RF Wireless Misc UHF (1kbit r/w anti-collision)
• Manufacturer: Atmel

13.7.3
13.7.4
4817C–RFID–03/07
Further Possibilities with Anticollision_ID Command
Group_AFI
The start address of the arbitration can be selected by the parameter field.
Table 13-5.
If parameter(7) is set to “1”, the arbitration starts with a 16-bit random value. The memory con-
tents follows. Therefore, the deterministic anticollision procedure can also handle ID structures
which are not unique, opening a migration path from other data systems towards ATA5590.
Figure 13-3. Flow Considering the Random Value
The Group_AFI command is based on the AFI byte stored in the Tag_ID page of the control
memory. The Group_AFI command affects the pre_select flag.
The flag will be set if:
If the reader transmits a 00h, the real value inside the EEPROM is ignored. As long as the
reader transmits a series of logical 0’s, ATA5590 does not stop backscattering the real value.
Note:
ID Page
Block 3
Block 2
Block 1
Block 0
Note:
• Parameter(3): If set to “0”, the arbitration starts in block 3 of the ID page; if set to “1”, it starts
• Parameter(5:4) points to the byte of the selected block
• The contents of the AFI field is the same, or
• The reader has transmitted 00h.
with block 2 of the ID page.
The Group_AFI command considers this mechanism only for the first 8 bits. Then the default arbi-
tration mechanism works.
Header
The value marked in bold is the default value.
Start Address of Arbitration as a Function of Parameter(5:3).
Command, parameter
Byte 3
110
111
EOT
Byte 2
100
101
Header
Random
16 bits
Arbitration
Byte 1
010
011
ID
EOF
CRC
Byte 0
000
001
ATA5590
EOT
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