TK5552A-PP Atmel, TK5552A-PP Datasheet - Page 15

• Manufacturer Part Number: TK5552A-PP
• Manufacturer: Atmel

Specifications of TK5552A-PP

• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Compliant

8.7.1
4698B–RFID–08/05
Downlink Data Coding
The duration of a field gap is typically between 80 µs and 250 µs. After the start gap the data bits
are transmitted by the base station whereby each bit is separated by a field gap. The bit decoder
interprets 16 to 32 internal field clocks as a logical 0 and 48 to 64 internal field clocks as a logical
1 (see
56 field clocks for a 1.
Whenever the bit decoder detects more than 64 field clocks, the transponder IC will abort the
downlink mode. The incoming data stream is checked continuously. If any error occurs, the cor-
responding error handling will be initiated.
The control logic initiates an EEPROM programming cycle if the correct number of bits had been
received (see
Figure 8-8.
Figure
8-8). Therefore, the time between two gaps is typically 24 field clocks for a 0 and
Figure
Operation of Bit Decoder – Data Stream Decoder
8-9).
count field clocks FC
YES
Enter error handler
Start gap detected
Downlink mode
FC count > 64 ?
gap detected ?
48
Uplink mode
Uplink mode
16
YES
NO
NO
NO
"Bit Error"
FC
FC
?
?
?
64
32
YES
YES
YES
NO
NO
'0' into shift register
'1' into shift register
Data stream check
TK5552
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