CR14_10 STMICROELECTRONICS [STMicroelectronics], CR14_10 Datasheet - Page 30

• Manufacturer Part Number: CR14_10
• Description: ISO14443 type-B contactless coupler chip with anti-collision and CRC management
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

CR14 ISO14443 type-B radio frequency data transfer
Figure 26. Example of a complete transmission frame
6.10
30/47
the CR14
Sent by
Case of Answer Frame with SOF & EOF
Case of Answer Frame without SOF & EOF
at 106Kb/s
Sent by the PICC
12 bits
SOF
CRC
The 16-bit CRC used by the CR14 follows the ISO14443 type B recommendation. For
further information, please see
The two CRC Bytes are present in all Request and Answer Frames, just before the EOF.
The CRC is calculated on all the Bytes between the SOF and the CRC Bytes.
Upon transmission of a Request from the CR14, the PICC verifies that the CRC value is
valid. If it is invalid, it discards the frame and does not answer the CR14.
Upon reception of an Answer from the PICC, the CR14 verifies that the CRC value is valid. If
it is invalid, it stores the value FFh in the Input/Output Frame Register.
The CRC is transmitted Least Significant Byte first. Each Byte is transmitted Least
Significant Bit first.
Figure 27. CRC transmission rules
Output Data Transfer using ASK Modulation
10 bits
Cmd
10 bits
Data
t DR
10 bits
CRC
LSBit
10 bits
CRC 16 (8 bits)
CRC
Doc ID 11922 Rev 2
LSByte
Appendix A on page
10 bits
EOF
MSBit LSBit
64/f s Min
64/f s Min
t 0
t 0
t WDG
t WDG
f s = 847.5kHz
80/f s Min
80/f s Min
Sync
Sync
CRC 16 (8 bits)
t 1
t 1
Input Data Transfer using 847kHz BPSK Modulation
44.
MSByte
12 or 13
10 bits
Data
SOF
bits
10 bits
Data
MSBit
10 bits
Data
ai09256
10 bits
Data
10 bits
CRC
10 bits
CRC
10 bits
CRC
10 bits
CRC
12 or 13
EOF
bits
ai12052
CR14