XE8000EV108 Semtech, XE8000EV108 Datasheet - Page 105

• 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

14.12.2.5 Transmission mode using NRZ coding
This RF link uses a wide band transmission in the 915MHz frequency band. The protocol of the messages to be
sent is NRZ Level. The start sequence of the message is a 4 byte pattern (10101010 10101010 10101010
11010100). The messages have a data rate of 76.8 kbit/s with a frequency deviation of 100 kHz. The output power
is 0 dBm. The following paragraphs will show how to set-up the XE1202A, how to set-up the RF interface and how
to handle the received data.
14.12.2.5.1
To set the XE1202A in transmission mode, set the pins MODE(2:0) = 111.
To select the 915MHz band, the bits FSParam_band = 11. The frequency deviation is set to 100kHz by writing
RTParam_Dev = 11. The baud rate is set to 76.8 kbit/s by writing FSParam_BR = 100. The output power is set to 0
dBm by writing RTParam_Tpow = 00. The setup of the XE1202a is shown in Table 14-31.
14.12.2.5.2
We then set-up the RF interface of the microcontroller circuit as a transmitter (RfifEnRx = 0 and RfifEnTx = 1).
Assume that the RC clock frequency used in the microcontroller is 1.2 MHz. To select the correct baud rate of 76.8
kbit/s according to the equation in chapter 14.10, fine*coarse=1.2e06/(16*76.8e3)=0.98. We can approximate this
at 1 (see specification in Table 14-19). This can be done by setting RfifBRCoarse = 00 and RfifBRFine = 0000.
The external bit synchronization clock is switched off by clearing the bit RfifTxClock = 0.
The encoder is enabled and set to NRZ Level encoding by setting RfifEnCod = 1 and RfifPCM = 000.
The set-up of the interface is summarized in the Table 14-32.
© Semtech 2006
Register
RTParam1
RTParam2
FSParam1
FSParam2
FSParam3
DataOut
ADParam1
ADParam2
Pattern1
Pattern2
Pattern3
Pattern4
Table 14-31. XE1202A register set-up (see XE1202A datasheet for bit explanation)
XE1202A set-up
RF interface set-up
Register Address
RegRfifCmd1
RegRfifCmd2
RegRfifCmd3
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
Register
Table 14-32. RF interface set-up
14-25
0
0
1
0
0
0
0
0
0
0
0
0
7
0
1
1
0
0
0
0
0
0
0
0
0
6
0
0
1
0
0
0
0
0
0
0
0
0
5
00000000
00100010
00000001
contents
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
1
0
0
0
0
0
0
0
0
0
2
XE8806A/XE8807A
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
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