EM4069
EM4169
ROM organization
The ROM is composed of 64 bits divided in a 9-bit header, 10 nibbles of 4 data bits and 1 row even parity bit, 4 column even
parity bits, and 1 stop bit. The Read ROM command will output the contents of the ROM, starting with bit-0. When bit-64 is
output, the sequence continues with bit-0.
Data in ROM is written by laser programming during manufacturing to form a unique identification code.
Figure below presents the ROM data structure. Bits P0 to P9 are row parity bits and bits PC0 to PC3 are column parity bits.
Parity is even so that a 9 bits set to logic one header can not be reproduced in a data stream.
Bit 0
1
1
1
1
1
1
1
1
1
Bit 8
Header
Bit 9
D00
D10
D20
D30
D40
D50
D60
D70
D80
D90
PC0
D01
D11
D21
D31
D41
D51
D61
D71
D81
D91
PC1
D02
D12
D22
D32
D42
D52
D62
D72
D82
D92
PC2
D03
D13
D23
D33
D43
D53
D63
D73
D83
D93
PC3
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
0
Bit 13
Bit 18
Bit 23
Bit 28
Bit 33
Bit 38
Bit 43
Bit 48
Bit 53
Bit 58
Bit 63
8 bits customer ID
Bit 14
Bit 19
Bit 24
Bit 29
Bit 34
Bit 39
Bit 44
Bit 49
Bit 54
Bit 59
Unique
device
serial
number
Column parity bits
Fig. 8
Customer ID for all standard versions is 01 hex.
Command description
The EM4069 operates in different modes. The default following a Power on Reset is Read EEPROM mode, and by means of
different commands, the circuit can switch to the following modes :
ꢀ
ꢀ
ꢀ
ꢀ
read access to ROM
write access to 16 bits of EEPROM
write access to configuration word
read access to configuration word
The reader has to generate the commands, which have to be decoded by the EM4069.
Command
Command
Bit pattern
Function
Short name
Command 1
Command 2
Command 3
Command 4
Command 5
rst
rROM
wr
1010 0000
1010 0101
Reset and return to EEPROM read
READ 64 bit ROM
1100.add.data.crc WRITE 16 bit EEPROM word
1101 0011.prot.crc WRITE configuration word
wcw
rcw
1111 0000
Read configuration word
Commands rst, rROM and rcw affect readout. An eight-bit pattern has to be sent to execute them. Write commands are longer
since associated address and data have to be sent. The leftmost bit in command bit pattern is transferred first.
Command 1: Reset command
Command 4 : Write configuration word
During activation of the transponder a return to default
mode is possible from any mode with the reset command.
Command 4 has the same structure as command 3. The
16-bit configuration word is written by this command. A
partial locking (write inhibit) of the 128 bit memory is
possible in blocks of 16 bits (16 bit word becomes read-
only).
Command 2 : Read out of ROM 64 Bits
After activation of command 2, the 64 bit ROM data will be
read out cyclically. This mode will be active until power
down or reset command.
The bits of configuration word are OTP (one time
programmable) so once a certain bit in configuration word
is set it cannot be reset.
Command 3 : Write 16 Bit EEPROM word
After activation of command 3, a 16-bit EEPROM word can
be written. Data transmission will be secured by CRC
check information, which has to be calculated by the reader
and which will be checked by the EM4069.
7
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