CLRC663 Datasheet, PDF (45/132 Pages) NXP Semiconductors – Contactless reader IC

NXP Semiconductors
CLRC663
Contactless reader IC
8.6.5 Symbol generator
The symbol generator is used to create various protocol symbols. These can be e.g. SOF
or EOF symbols as they are used by the ISO14443 protocols or proprietary protocol
symbols like the CS symbol as used by the ICODE EPC protocol.
Symbols are defined by means of the symbol definition registers and the mode registers.
Four different symbols can be used. Two of them, Symbol0 and Symbol1 have a
maximum pattern length of 16 bit and feature a burst length of up to 256 bits of either logic
“0” or logic “1”. The Symbol2 and Symbol3 are limited to 8 bit pattern length and do not
support a burst.
The definition of symbol patterns is done by writing the bit sequence of the pattern to the
appropriate register. The last bit of the pattern to be sent is located at the LSB of the
register. By setting the symbol length in the symbol-length register (TxSym10Len and
TxSym32Len) the definition of the symbol pattern is completed. All other bits at
bit-position higher than the symbol length in the definition register are ignored. (Example:
length of Symbol2 = 5, bit7 and bit6 are ignored, bit5 to bit0 define the symbol pattern, bit5
is sent first)
Which symbol-pattern is sent can be configured in the TxFrameCon register. Symbol0,
Symbol1 and Symbol2 can be sent before data packets, Symbol1, Symbol2 and Symbol3
can be sent after data packets. Each symbol is defined by a set of registers. Symbols are
configured by a pair of registers. Symbol0 and Symbol1 share the same configuration and
Symbol2 and Symbol3 share the same configuration. The configuration includes setting of
bit-clock- and subcarrier-frequency, as well as selection of the pulse type/length and the
envelope type.
8.7 Memory
8.7.1 Memory overview
The CLRC663 implements three different memories: EEPROM, FIFO and Registers.
At startup, the initialization of the registers which define the behavior of the IC is
performed by an automatic copy of an EEPROM area (read/write EEPROM section1 and
section2, register reset) into the registers. The behavior of the CLRC663 can be changed
by executing the command LoadProtocol, which copies a selected default protocol from
the EEPROM (read only EEPROM section4, register Set Protocol area) into the registers.
The read/write EEPROM section2 can be used to store any user data or predefined
register settings. These predefined settings can be copied with the command
"LoadRegister" into the internal registers.
The FIFO is used as Input/Out buffer and is able to improve the performance of a system
with limited interface speed.
CLRC663
Product data sheet
COMPANY PUBLIC
All information provided in this document is subject to legal disclaimers.
Rev. 3.3 — 3 April 2012
171133
© NXP B.V. 2012. All rights reserved.
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