CRX14_05 Datasheet, PDF (22/40 Pages) STMicroelectronics – Low Cost ISO14443 type-B Contactless Coupler Chip with Anti-Collision, CRC Management and Anti-Clone Function

CRX14
Table 7. CRX14 Request Frame Character Format
Bit
Description
b₀
Start bit used to synchronize the transmission
b₁ to b₈
Information Byte (instruction, address or data)
b₉
Stop bit used to indicate the end of the character
Value
b₀ = 0
Information Byte is sent Least Significant Bit
first
b₉ = 1
Request Start Of Frame
The Start Of Frame (SOF) described in Figure 22.
consists of:
– 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’.
Figure 22. Request Start Of Frame
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 b10 b11
ETU 0 0 0 0 0 0 0 0 0 0 1 1
ai09251
Request End Of Frame
The End Of Frame (EOF) shown in Figure 23. con-
sists of:
– a falling edge,
– followed by ten Elementary Time Units (ETU)
containing each a logical ‘0’,
– followed by a single rising edge.
Figure 23. Request End Of Frame
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9
ETU 0 0 0 0 0 0 0 0 0 0
ai09252
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