AT88RF1354_09 ATMEL [ATMEL Corporation], AT88RF1354_09 Datasheet - Page 27

• Manufacturer Part Number: AT88RF1354_09
• Description: 13.56 MHz Type B RF Reader Specification
• Manufacturer: ATMEL [ATMEL Corporation]

A.6.
A.7.
8547B–RFID–3/09
Subcarrier Off
When the subcarrier is turned on it remains unmodulated for a time period known as the synchronization time (TR1).
The phase of the subcarrier during TR1 defines a logical one and permits the reader demodulator to lock on to the
subcarrier signal. The subcarrier remains on until after the EOF transmission is complete.
Figure A-4.
Response Timing
After the PICC receives a command from the PCD, it is not permitted to transmit a subcarrier during the guard time
(TR0). The minimum guard time is 8 ETUs for all command responses. The maximum guard time is defined by the
frame waiting time (FWT), except for the ATQB response (response to REQB or Slot MARKER polling commands)
which has a maximum TR0 of 32 ETUs.
Figure A-5.
The FWT is the maximum time that a PICC requires to begin a response. The PICC transmits a parameter in the ATQB
response to the polling command that tells the reader the worst case FWT. The PCD is not permitted to modulate the
RF field while waiting for a PICC to respond to a command. Modulation of the RF field during a PICC memory read or
write operation may corrupt the operation or cause reset of the PICC.
CRC Error Detection
A 2 byte CRC_B is required in each frame transmitted by the PICC or PCD to permit transmission error detection. The
CRC_B is calculated on all of the command and data bytes in the frame. The SOF, EOF, start bits, stop bits, and EGT
are not included in the CRC_B calculation. The two byte CRC_B follows the data bytes in the frame.
Reader/Writer
PICC (Chip)
Subcarrier On
Format of a frame transmitted by the PICC to the reader.
ISO/IEC 14443 response timing requirements for the card.
TR1
CRC
Subcarrier OFF
SOF
EOF
13.56 MHz Type B RF Reader Specification
Transmit Data and CRC_B
TR0
Data Transmission
No Modulation
Subcarrier ON
TR1
Unmodulated Carrier
EOF
SOF
Subcarrier Off
Response
Data
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