XE8000EV108 Semtech, XE8000EV108 Datasheet - Page 100

• Manufacturer Part Number: XE8000EV108
• Description: EVAL BOARD FOR XE8806/XE8807
• Manufacturer: Semtech
• Type: MCUr

Specifications of XE8000EV108

• Contents: Fully Assembled Evaluation Board
• For Use With/related Products: XE88LC06AMI026
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

XE8806A/XE8807A
14.12.1.5.3
Data transmission
To handle the transmission data by interrupt, enable the RF interface transmission interrupt in the interrupt handler
of the circuit.
We need to send the start sequence first. The start sequence is defined as a protocol violation. To send a protocol
violation, the encoder has to be disabled by clearing RfifEnCod = 0. We then can write for instance “00000000” to
RfifTx.
At occurrence of the interrupt, the start sequence was transferred to the shift register and the FIFO is empty. The
encoder is to be enabled by setting RfifEnCod = 1. We do not need to wait until the start sequence transmission is
completed, since the modification of the bit RfifEnCod is taken into account only at the transfer of the next byte
from the FIFO to the transmission shift register. The first 4 bytes of the message can then be written to RfifTx.
At each occurrence of the interrupt, 4 bytes of the message can be written to the FIFO until the end of the message
is reached. The whole operation starts over again for the next message.
14.12.2
Using the RF interface with the XE1202A
This chapter gives some examples on how the RF interface can be used with the XE1202A circuit. It does not
describe all possibilities but selects some representative cases.
14.12.2.1 Microcontroller – transceiver connections
For the external components required to operate the XE1202A, please refer to the XE1202A datasheet.
The connections between the XE8000 microcontroller and the XE1202 are shown in Figure 14-9. The transmission
data are connected between the RF interface of the microcontroller and the transceiver. The configuration lines of
the XE1202A can be driven by pins of a parallel port. The 3-wire configuration data bus of the XE1202A is used to
set-up the circuit by writing in the registers RTParam, FSParam, ADParam and Pattern. The interface can be
driven by a hardware SPI or by a software SPI on a parallel port. Pins of the RF interface RFIF0 to RFIF3 that are
not used may remain floating.
If the XE1202A is used as a transmitter only, the connections RFIF0 – RXD, RFIF1 – CLKD and RFIF2 –
PATTERN are not required.
If the XE1202A is used as a receiver only, the connection RFIF3 – TXD is not required. If the bit synchronizer in the
XE1202A is not used, the connection RFIF1 – CLKD is not required. If the start sequence detection is not used, the
connection RFIF2 – PATTERN is not required.
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