srix4k STMicroelectronics, srix4k Datasheet - Page 9

• Manufacturer Part Number: srix4k
• Description: 13.56mhz Short Range Contactless Memory Chip With 4096 Bit Eeprom, Anti-collision And Anti-clone Functions
• Manufacturer: STMicroelectronics

SRIX4K
3
3.1
3.1.1
Data transfer
Input data transfer from the Reader to the SRIX4K (request
frame)
The reader must generate a 13.56 MHz sinusoidal carrier frequency at its antenna, with
enough energy to “remote-power” the memory. The energy received at the SRIX4K’s
antenna is transformed into a supply voltage by a regulator, and into data bits by the ASK
demodulator. For the SRIX4K to decode correctly the information it receives, the reader
must 10% amplitude-modulate the 13.56 MHz wave before sending it to the SRIX4K. This is
represented in
Figure 3.
Character transmission format for request frame
The SRIX4K transmits and receives data bytes as 10-bit characters, with the least
significant bit (b
(Elementary Time Unit), is equal to 9.44 µs (1/106 kHz).
These characters, framed by a Start Of Frame (SOF) and an End Of Frame (EOF), are put
together to form a Command Frame as shown in
commands, addresses, data, a CRC and an EOF as defined in the ISO 14443-3 Type B
Standard. If an error is detected during data transfer, the SRIX4K does not execute the
command, but it does not generate an error frame.
Figure 4.
10% ASK MODULATION
OF THE 13.56MHz WAVE,
GENERATED BY THE READER
DATA BIT TO TRANSMIT
TO THE
1 ETU
SRIX4K
Start
"0"
b0
10% ASK modulation of the received wave
SRIX4K request frame character format
Figure
0
) transmitted first, as shown in
LSb
b1
3. The data transfer rate is 106 Kbits/s.
b2
b3
Information Byte
b4
Transfer time for one data bit is 1/106 kHz
b5
Figure
Figure
b6
4. Each bit duration, an ETU
b7
10. A frame includes an SOF,
MSb
b8
Stop
"1"
b9
Data transfer
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