EM4170
Commands
The commands are composed of 4 bits, divided into 3 data bits and 1 even parity bit (total amount of "1's" is even including
the parity bit). There exist 6 different commands. Upon reception of an unknown command or a command with wrong parity
the chip will immediately return into Standby Mode.
Commands
FUNCTION
ID-MODE
UM-MODE-1
AUTHENTICATION
WRITE WORD
SEND PIN
UM-MODE-2
COMMAND BITS
001 1
010 1
011 0
101 0
100 1
111 1
First bit
Recieved
Parity bit
Fig. 5
ID Mode
After reception of the command including the parity the chip sends a header consisting of 12 Manchester coded '1's
followed by 4 Manchester coded '0's. Then the chip sends the 32 Bits of ID contained in words 3 and 2 of the EEPROM
once without parity starting with the MSB of word 3. After completion the chip returns to Standby-Mode.
t
rID
Header
OUTPUT
LIW
RM
Command
1111111111110000
D31-D0
LIW
INPUT
1 bit - 32 T0 periods
Data
Coded Data
T0 = Period of RF carrier frequency
Fig. 6
UM-MODE-1
In UM-MODE-1 the chip sends LB1 and LB0 followed by the 30 Bits of UM1 starting with the MSB following the same
procedure as in ID-MODE. After completion the chip returns to Standby Mode
Copyright
2002, EM Microelectronic-Marin SA
6
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EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
