P4069 EM Microelectronic, P4069 Datasheet - Page 9

• Manufacturer Part Number: P4069
• Description: 128 Bit Read/write Contactless Identification Device With Otp Function
• Manufacturer: EM Microelectronic

configuration word command is compatible to Write
Word command:
1101 0011 [8 bits protecting 8 words] [8 bits don’t
care] [8 bit CRC]
8 bits protecting 8 words:
Bit first sent in is protecting word 0, the second bit
protects word 1 and so on.
8 bits don’t care:
Any 8-bit pattern, all 0 pattern is not suggested for
power supply reasons.
CRC has to be correct including also don’t care bits.
Example of Write Configuration Word command:
D3 02 55 2F (hex)
The above command (1101 0011) will protect word 6
(0000 0010) from being written.
If later on, word 1 has to be protected, the protection
bit of already protected word 6 has to be set to logic 1
again. The new command will have to be sent with
the following protection bits: 0100 0010.
Read Configuration word Command
To enter this command the IC has to be in default
mode (read EEPROM bits). After execution of this
command the IC will cyclically read 128 bits.
16 of them will represent the configuration word the
rest is 0. It is suggested that don’t care bits of
configuration word are programmed with some
pattern which will be easy to recognize during read
out.
Command Timing for 8-bit command
While IC is in Read mode it is sampling the peak
level of coil voltage (during the time modulator switch
is ON) once every bit period. The peak to peak value
is compared with an internal reference in order to get
a one-bit information (high field or low field). The
measured level is compared with previous samples in
out Read
in
Sync. wcw
The
EM MICROELECTRONIC-MARIN SA
bit
t
Wee
pattern
of
1ms
the
Figure 11
Read
Write
order to detect whether there is a reader-induced
modulation present on the magnetic field.
Commands are accepted in the range where normal
field (100% strength) is higher than internal reference
(considered as high field) and modulated field is
lower than internal reference (considered as low
field). An 65% modulation on the reader signal is
proposed (high field 100%, low field 20%).
When the synchronization pattern of modulation on
magnetic field is detected (Command Envelope) the
P4069 waits for a Start Bit (SB).
If the start bit is detected before t
expired, the Command
Eight command bits are serially entered. After the last
bit was shifted, the 8-bit pattern is compared to one
of the 5 possible commands. In the case one of the
commands is recognized the appropriate action is
performed otherwise the IC returns in Read mode.
Detection of Command Envelope
The Peak Detector performs the measurement once
every bit period. The Peak Detector circuit compares
the peak value of voltage on the coil to the internal
voltage reference. The result of comparison is one bit
of information, which tells to Control Logic whether
the field is strong (HIGH field) or weak (LOW field).
The Peak Detector circuit has a built-in hysteresis of
typically 100mV which prevents unwanted Envelope
detection in field strength which is at the level of the
Detector threshold.
Detection of Start Bit (SB) and Command Word
After the Synchronization pattern Envelope was
detected, the P4069 is sampling the incoming signal
at a T
when three consecutive samples are LOW.
Duration of start bit (version 64 clocks/bit) and
following command bits are expected to be 512 µs
(same as one bit period in read mode). In the version
32 clocks/bit, the duration is 256 µs
When the start bit is detected, the Control Logic
starts switching Modulator load OFF and ON (First
half of bit period OFF and second half of bit period
ON) to assure enough power for operation of the IC.
Samples of incoming bits are taken during the time
the modulator load is ON (connected).
The command, address, data and CRC bits are sent
in non coded form (NRZ), reader induced high field
(non modulated) corresponds to logic one, low field
(modulated) to logic zero.
RDB
/8 rate. The start bit is accepted as valid
P4069/P4169
Processing mode is entered.
S3
time-out is
9