T555711-TAS Atmel, T555711-TAS Datasheet - Page 7

• Manufacturer Part Number: T555711-TAS
• Description: IC IDIC R/W RFID 330BIT 8-SOIC
• Manufacturer: Atmel
• Series: T555711r

Specifications of T555711-TAS

• Rf Type: Read / Write
• Frequency: 125kHz
• Features: 330-bit EEPROM
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.3
4.4
4.5
4517J–RFID–03/06
Regular-read Mode
Block-read Mode
e5550 Sequence Terminator
In regular-read mode data from the memory is transmitted serially, starting with block 1, bit 1, up
to the last block (e.g., 7), bit 32. The last block which will be read is defined by the mode param-
eter field MAXBLK in EEPROM block 0. When the data block addressed by MAXBLK has been
read, data transmission restarts with block 1, bit 1.
The user may limit the cyclic datastream in regular-read mode by setting the MAXBLK between
0 and 7 (representing each of the 8 data blocks). If set to 7, blocks 1 through 7 can be read. If
set to 1, only block 1 is transmitted continously. If set to 0, the contents of the configuration block
(normally not transmitted) can be read. In the case of MAXBLK = 0 or 1, regular-read mode can
not be distinguished from block-read mode.
Figure 4-1.
Every time the T5557 enters regular- or block-read mode, the first bit transmitted is a logical “0”.
The data stream starts with block 1, bit 1, continues through MAXBLK, bit 32, and cycles contin-
uously if in regular-read mode.
Note:
With the direct access command, the addressed block is repetitively read only. This mode is
called block-read mode. Direct access is entered by transmitting the page access opcode (“10”
or “11”), a single “0” bit and the requested 3-bit block address when the tag is in normal mode.
In password mode (PWD bit set), the direct access to a single block needs the valid 32-bit pass-
word to be transmitted after the page access opcode whereas a “0” bit and the 3-bit block
address follow afterwards. In case the transmitted password does not match with the contents of
block 7, the T5557 tag returns to the regular-read mode.
Note:
The sequence terminator ST is a special damping pattern which is inserted before the first block
and may be used to synchronize the reader. This e5550-compatible sequence terminator con-
sists of 4 bit periods with underlaying data values of “1”. During the second and the fourth bit
period, modulation is switched off (Manchester encoding – switched on). Biphase modulated
data blocks need fixed leading and trailing bits in combination with the sequence terminator to
be identified reliable.
The sequence terminator may be individually enabled by setting of mode bit 29 (ST = “1”) in the
e5550-compatibility mode (X-mode = “0”).
MAXBLK = 5
MAXBLK = 2
MAXBLK = 0
This behavior is different from the original e555x and helps to decode PSK-modulated data.
A direct access to block 0 of page 1 will read the configuration data of block 0, page 0.
A direct access to bock 3 to 7 of page 1 reads all data bits as zero.
Examples for Different MAXBLK Settings
Loading block 0
Loading block 0
Loading block 0
0
0
0
Block 1
Block 1
Block 0
Block 4
Block 2
Block 0
Block 5
Block 1
Block 0
Block 1
Block 2
Block 0
Block 2
Block 1
Block 0
T5557
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