
AT88RF1354 SPI User Guide For CryptoRF
®
2.3.4
Smart Poll Mode Operation
Smart Poll mode is enabled by sending the Poll Continuous command with N = 111b. In the
Smart Poll mode, the reader will continually send REQB/WUPB with N = 000b until it receives a
card response. If this response is valid, it will return the response to the host. If the card response
generates a communication error, the reader assumes that there was a collision. It will then send
the next REQB/WUPB with N = 001b, and if there is no valid card response it will send Slot-
MARKER for slot two.
If there is no response from a card in either slot, then the reader returns to polling with N = 000b.
If there is an error free card response, then it will be returned to the host. If there is another
collision and no valid response, however, N will again be incremented, and the reader will send
the correct sequence of REQB/WUPB and Slot-MARKERs. In the case where Smart Poll mode
reaches 16 slots and only collisions are detected, then polling is stopped, and a Smart Poll error
code is returned to the host. If no error-free card response is detected, then polling continues until
an Abort command is sent by the host.
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8586A—RFID—5/09