SLRC400 datasheet(99/130 Pages) PHILIPS

99 / 130 page

Philips Semiconductors

Product Specification Rev. 2.0 November 2001

•CODE Reader IC

SL RC400

Preliminary

16.4.1.2 RF-Channel Redundancy and Framing

Each transmitted ISO 15693 frame consists of a SOF (start of frame) pattern, followed by the data stream

and is closed by an EOF (end of frame) pattern. All I

•CODE1 command frames consists of a START PULSE

followed by the data stream. The I

•CODE1 commands have a fix length and no EOF is needed. These

different phases of the transmit sequence may be monitored by watching ModemState of PrimaryStatus-

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

16.4.1.3 Transmission of Frames with more than 64 Bytes

To generate frames with more than 64 bytes, the µ-Processor has to write data into the FIFO buffer while the

Transmit Command is active. The state machine checks the FIFO status when it starts transmitting the last

bit of the actual data stream (the check time is marked below with arrows).

As long as the internal signal ‘Accept Further Data’ is 1 further data may be loaded into the FIFO. The

SL RC400 appends this data to the data stream transmitted via the RF-interface.

If the internal signal ‘Accept Further Data’ is 0 the transmission will terminate. All data written into the FIFO

buffer after ‘Accept Further Data’ went 0 will not be transmitted anymore, but remain in the FIFO buffer.

FIFO Length

FIFO empty

0x01

0x00

TxLastBits = 0

TxLastBits

Bit0

Bit7 Bit0

Bit7

TxData

Check FIFO empty

Accept Further Data

Bit7

Figure 16-1: Timing for Transmitting Byte Oriented Frames

SLRC400 Datasheet(PDF) 99 Page - NXP Semiconductors