EM4170
Word Organisation
First bit input
Data
Row Even Parity
D15
D11
D07
D03
PC3
D14
D10
D06
D02
D13
D09
D05
D01
D12
D08
D04
D00
PC0
P3
P2
P1
P0
0
PC2 PC1
Column Even Parity
Last bit input
logic "0"
Fig. 10
After reception of the write command, the address and the data, the EM4170 will check the parity and the Lock-Bits. If all
the conditions are fulfilled, an Acknowledge pattern (ACK) will be issued, and the EEPROM writing process will start. At the
end of programming the chip will send an Acknowledge pattern (ACK). If at least one of the checks fails, the chip will issue
a No Acknowledge pattern (NAK) instead of ACK and return to the Standby Mode.
The EM4170 might also return to the Standby 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 (V
DD
≥2.6V),
when performing the write command.
Write word
T
wa
t
wee
OUTPUT
LIW
ACK
ACK
LIW
INPUT
RM
WRITE WORD
ADDRESS
DATA
Fig. 11
Write Word
Begin
Receive
Command
valid ?
Y
Send
ACK
N
Receive
Address
Receive
Data
Write
Data
Send
ACK
Send
NAK
End
Fig. 12
Copyright
2002, EM Microelectronic-Marin SA
8
www.emmicroelectronic.com
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
