CR14_10 STMICROELECTRONICS [STMicroelectronics], CR14_10 Datasheet - Page 32

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

Tag access using the CR14 coupler
Figure 29. Standard TAG command: answer frame reception
Figure 30. Standard TAG command: complete TAG access description
7.2
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I²C
RF
I²C
RF
START
TAG
SOF
SOF
Device
Select
Code
Write
Register
Address
Anti-collision TAG sequence
The CR14 can identify an ST short range memory using a proprietary anti-collision system.
Issuing an I²C Write command to the Slot Marker Register
automatically generate a 16-slot anti-collision sequence, and to store the identified Chip_ID
in the Input/Output Frame Register, as specified in
After receiving the Slot Marker Register I²C Write command, the CR14 generates an RF
PCALL16 command followed by fifteen SLOT_MARKER commands, from
SLOT_MARKER(1) to SLOT_MARKER(15). After each command, the CR14 waits for a tag
answer. If the answer is correctly decoded, the corresponding Chip_ID is stored in the
Input/Output Frame Register. If there is no answer, or if the answer is wrong (with a CRC
error, for example), the CR14 stores an error code in the Input/Output Frame Register. At
the end of the sequence, the host has to read the Input/Output Frame Register to retrieve all
the identified Chip_IDs.
Data 1
TAG
Data
I/O
Request
Data 2
Length
Frame
TAG
Data
Request
Data
TAG
Data
Frame
Bytes
Data P
STOP
TAG
Data
SOF
Characters
Request
CRC
Frame
TAG
CRC
Doc ID 11922 Rev 2
CRC
TAG
CRC
CRC
EOF
<-->
EOF
T 0
TAG
EOF
<-->
T 1
SOF
S
T
A
R
T
Device
Select
Code
Answer Frame
Characters
Table
TAG
Register
Address
Output
Input/
01h
4.
(Figure
Answer
Length
Frame
CRC
P
EOF
START
Data 1
Data
TAG
16) causes the CR14 TO
Device
Select
Code
Read
TAG
Data
Data 2
Answer
Length
Frame
TAG
Data
Data
Request
Frame
Bytes
Data P
ai09262
TAG
Data
ai09261
STOP
CR14
S
T
O
P