CR14 STMicroelectronics, CR14 Datasheet - Page 27

• Manufacturer Part Number: CR14
• Description: Low Cost Iso14443 Type-b Contactless Coupler Chip With Anti-collision And Crc Management
• Manufacturer: STMicroelectronics

CR14
6.2
6.3
Transmission Format of Request Frame Characters
The CR14 transmits characters of 10 bits, with the Least Significant Bit (b
shown in
Several 10-bit characters, preceded by the Start Of Frame (SOF) and followed by the End Of
Frame (EOF), constitute a Request Frame, as shown in
A Request Frame includes the SOF, instructions, addresses, data, CRC and the EOF as
defined in the ISO14443 type-B.
Each bit duration is called an Elementary Time Unit (ETU). One ETU is equal to 9.44µs (1/
106kHz).
Figure 20. CR14 Request Frame Character Format
Table 7.
Request Start Of Frame
The Start Of Frame (SOF) described in
Figure 21. Request Start Of Frame
b
b
b
0
1
9
to b
Bit
a falling edge,
followed by ten Elementary Time Units (ETU) each containing a logical ‘0’
followed by a single rising edge
followed by two ETUs, each containing a logical ‘1’.
8
Figure
Start bit used to synchronize the transmission
Information Byte (instruction, address or data)
Stop bit used to indicate the end of the character
CR14 Request Frame Character Format
20.
ETU
ETU
1
Start
b0
b 0
'0'
0
LSB
b 1
b1
0
Description
b 2
b2
0
b 3
b3
0
Figure 21
Information Byte
b 4
b4
0
6 CR14 ISO14443 type-B Radio Frequency data transfer
b 5
b5
0
consists of:
b 6
b6
0
Figure
b 7
b7
b
Information Byte is sent Least
Significant Bit first
b
0
0
9
= 0
= 1
MSB Stop
26.
b 8
b8
0
b 9
b9
'1'
0
0
b 10
Value
) transmitted first, as
1
b 11
1
ai12049
ai12050
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