CLRC632 Datasheet, PDF (116/163 Pages) NXP Semiconductors – Multiple Protocol Contactless Reader IC

Philips Semiconductors
Product Specification Rev. 3.0; May 2003
Multiple Protocol Contactless Reader IC
CL RC632
Depending on the setting of bit TxCRCEn in the ChannelRedundancy-Register a CRC is calculated and
appended to the data stream. The CRC is calculated according the settings in the ChannelRedundancy
Register. Parity generation is handled according the settings in the ChannelRedundancy-Register (bits
ParityEn and ParityOdd).
18.4.1.3 Transmission of Bit Oriented Frames
The transmitter may be configured to send an incomplete last byte. To achieve this TxLastBits has to be set
to a value unequal zero. This is shown in the figure below.
TxLastBits = 0
SOF Bit0
Bit7 P Bit0
Bit7 P
EOF
TxLastBits = 7
SOF Bit0
Bit7 P Bit0
Bit6 EOF
TxLastBits = 1
SOF Bit0
Bit7 P Bit0 EOF
Figure 18-1: Transmitting Bit Oriented Frames
The figure shows the data stream if ParityEn is set in ChannelRedundancy-Register. All fully transmitted
bytes are followed by a parity check bit, but the incomplete byte is not followed by a parity check bit.
After transmission, TxLastBits is cleared automatically.
Note: If TxLastBits is not equal to zero CRC generation has to be disabled. This is done by clearing the bit
TxCRCEn in the ChannelRedundancy Register.
116
Confidential