EM4170
SEND PIN
In this mode after reception of the command, the chip receives the 32 bits of the ID and the 32 bits of the PIN. If the
received data are valid, the chip will answer an ACK and write the lock bit LB0 to 0; then it will send back the header (12
« 1 » and 4 « 0 ») followed by the ID. Then the chip returns to Stand-by Mode. If the ID or the PIN are not valid, the chip
sends back a NACK and return to Stand-by Mode.
The EM4170 might also return to Stand-by Mode without sending back a NAK if the incoming data is corrupted and / or
inconsistent.
As there is no check of the power supply before writing, the system has to assure that there is enough power received by
the tag (VDD≥2.6V), when performing the send pin command.
After a successful SEND PIN command, it is recommended to check the content of the word 1 with the UM1 command.
Begin
Receive
Command
valid ?
N
Y
Receive
ID
Send
ACK
Receive
PIN
Write
LB0=0
Send
header
Send
NAK
Send
ID
End
End
Twee
Twalb
OUTPUT
INPUT
ID
LIW
ACK
header
LIW
RM
command
ID
PIN
Fig. 13
UM-MODE-2
In UM-Mode-2 the chip sends the 64 bits of UM2. It starts with MSB of Word 15 and finishes with LSB of Words 12. The
chip is using the same procedure than in ID-Mode, by sending the header before the data bits.
After completion the chip returns to Stand-by Mode.
9
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