EM4205-EM4305
Chip Type
co6 – co9:
Encoder
Bits ct1 to ct4 of Word 0 indicate the member of the
compatible family of chips.
Bits co6 – co9 define the data encoding used by the
EM4205/4305 to send back its data to the transceiver (in
read only mode).
Chip Type
EM4205
EM4305
Encoder
Manchester
Bi-phase
Ct1..ct4
1000
co6 – co9
1000
1001
0100
Table 6
Other
not used
Table 9
Resonant Capacitor
Bits ct5 and ct6 are used to indicate resonant capacitor
value.
co10:
Not used
This bit must be set to logic 0.
Resonant cap
ct5 - ct6
co11:
Not used
This bit must be set to logic 0.
10
210 pF
01
250 pF
co12 - co13:
Delayed ON
11
330 pF
Bits Co12 - Co13 define the setting to allow control of the
Delayed On feature. This mode follows the ISO 11785
specification to allow for time anticipation of low to high
transitions. This feature is implemented for Bi-phase, and
Manchester data encodings.
other
not used
Table 7
Customer Code
Bits ct9 to ct18 are attributed to Customer code. Default
Customer code is 1000000000 (0x200 hex), where the
leftmost bit is ct18.
Bits ct0, ct7, ct8 and ct19 - ct31 are reserved for future use
and are set to 0.
Bi-phase
co12 – co13
Manchester
No delay
00
01
10
11
Delayed On – BP/8
Delayed On – BP/4
Word 1: Unique Identification Number
Word 1 is factory programmed with 32 bit Unique
Identification Number.
No delay
Table 10
Word 2: Password Word
The 32 bit Password word has to be sent to the
Since the Bit Period (BP) for Bi-phase and Manchester
data encodings is selectable between RF/8, RF/16, RF/32
and RF/64, the Delayed On feature is defined relative to
the bit period. The maximum Delayed On for Bi-phase
and Manchester is one quarter of the bit period.
Examples of Delayed On are shown in the figure below.
EM4205/4305 during
a Login command to enable
password protected operations.
The password word can not be read out with a read word
command.
Word 4: Configuration Word
FDX-B mode: Bi-phase, RF/32
The Configuration word is used to define the device-
operating modes and options, such as Encoder, Delayed
On and Login Protection.
The example shown in the figure 8 is for the configuration
as follows:
Delayed ON co12 – co13 = 10 => Delayed ON - BP/4
Delayed On
Delayed On
co0 – co5:
Data Rate
BP/4
BP/4
Bits co0 – co5 define the data rate used by the
EM4205/4305 to send back its data to the transceiver (in
read only mode). The data rates are valid for both data
encodings: bi-phase and Manchester.
0
1
1
0
Data Rate
RF/8
RF/16
RF/32
RF/40
RF/64
not used
Co0 – Co5
110000
111000
111100
110010
111110
other
Note 1
0.23845ms
0.23845ms
Figure 8
Note: For RF/40 data rate, the Delayed ON option is
configured as following:
Table 8
Bi-phase
Manchester
No delay
Note 1: RF/40 data rate only available on the EM4305 – 330pF
Cres version. RF/40 data rate is linked with Manchester and
Biphase data encodings.
co12 – co13
00
01
10
11
Delayed On – 8 RF clocks
Delayed On – 16 RF clocks
No delay
6
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Copyright 2013, EM Microelectronic-Marin SA
4205-4305-DS-01.doc, Version 4.0, 22-Oct-13
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
