SDBC-DK3UG Datasheet, PDF (53/76 Pages) Silicon Laboratories – 4 buttons and 4 LEDs for custom purposes

SDBC-DK3 UG
10. Si4432
The Si4432.c module contains code for all Si4432 related RF functions including RF setup parameters; Status
Read, Transmit, Receive, and Idle state. There is a global variable (a table) 'RfSettings', which contains the preset
modem parameters for each set of different data rates. These settings can be modified for other application
specific settings using values calculated based on the data sheet or through the EZRadioPRO Register Calculator
(available on WDS CDROM). It is suggested to change an entire line in the table if a new setting is desired
The RfInitHw () function initializes RF chip registers, I/O ports, timer, and IT routines needed by the RF stack. This
function has to be called in the power-on routine. Application specific parameters include: frequency band, carrier
frequency, TX/RX headers, sync words, modem setting, test bus and GPIO pin configurations.
Some of the core settings are listed below:
1. Read interrupt status to release the pending interrupts
2. SW reset -> wait for POR interrupt
3. Disable all ITs, except Chip Ready -- 'ichiprdy'
4. Set the non-default Si4432 registers
Set VCO
Set the AGC
Set ADC reference voltage to 0.9V
Set capacitance bank to adjust for adjust crystal PPM accuracy and TX/RX offsets
Reset digital testbus, disable scan test
Select nothing to the Analog Testbus
Set center frequency
Disable RX-TX headers
Set the sync word
Set GPIOs functionality
Set modem and RF parameters according to the selected DATA rate
The RFSetRfParameters() function configures the both the Tx and Rx RF parts of the radio for different
(predefined) data rates, deviations and modulation index requirements. This sets up all of the modem settings in
addition to the packet handler, CRC, preamble, and preamble detection threshold.
Note: The modem setting is a very important part of the RF parameters configuration. To simplify; there is a table in the code to
provide common parameter values for a number of data rate configurations, this can be seen below. The values shown
have been derived using the EZRadioPRO Register Calculator, available on the WDS CDROM or via the data sheet.
Rev. 0.4
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