AT24RF08-EK Atmel, AT24RF08-EK Datasheet - Page 13

• Manufacturer Part Number: AT24RF08-EK
• Description: KIT EVAL FOR AT24RF08CN-10SC
• Manufacturer: Atmel
• Type: Dual Access EEPROMr

Specifications of AT24RF08-EK

• Contents: Atmel Asset ID Kit CDROM, 4 RFID Tags, Reader with Serial Port Cable and 9V Power Supply
• For Use With/related Products: AT24RF08C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Reception: Decoding and Demodulation
For data received by the chip, a drop in amplitude is
interpreted as a low state, while an increase in amplitude
indicates a high state. The output of this demodulator is
inverted and then decoded using Manchester decoding
before being interpreted as commands or data.
In Manchester decoding, (sometimes called BiPhase),
there is a transition in the middle of each bit time. If this is a
high-to-low, the data state is a 0, and if low-to-high a 1.
Data is received by the chip at a rate of one bit (out of the
decoder) for each 64 carrier cycles.
Each command must be preceded by a command initiation
pattern (CIP). The receiver uses the leading edge of the
first modulation change of the CIP to automatically
synchronize to the incoming data stream. That edge must
occur during the t
previously transmitted or received by the chip. This edge is
Data Reception
CMD1
interval after the end of the last bit
used to start a bit clock against which all remaining edges
are timed.
The remaining two edges within the CIP occur during the
middle of the first and third bit times of the command. They
must occur within specific time intervals (t
beginning of the bit time, and their specific time locations
(within the bit times) are used to synchronize with
subsequent edges (t
(rising or falling). Edges that correspond to Manchester
changes at the beginning/end of a bit are not explicitly used
by the chip.
If no edges of the CIP fall within the t
read of some sort (including ID read), the chip will
retransmit the data that was previously read.
The following diagram shows functional waveforms for data
reception.
CMD3
AT24RF08C
) occurring in the same direction
CMD1
window after a
CMD2
) from the
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