3.4.2.4 Registers Involved In Analog Receive Path

The following registers are used by the analog receive path consisting of LNA, mixer and ADC. See also RF Front-End Register Description.

The RF front-end registers mentioned in the following must not be changed by application software. They are used by firmware to control the power-up and power-down of the receive path.

Table 3-7. RF Front-End Registers Used by Firmware
Register	Function
FESR.HBSAT	LNA High-Band saturated
FESR.LBSAT	LNA Low-Band saturated
FEEN1.ADEN	Analog-to-digital converter enable
FEEN1.ADCLK	Analog-to-digital converter clock enable
FEEN1.LNAEN	Low-noise amplifier enable
FEEN2.TMPM	Temperature measurement enable

The RF front-end values summarized in the preceding table are transferred from the factory-locked EEPROM to the RF front end by firmware before powering-up the receive path.

Table 3-8. RF Front-End Registers for Factory-Locked Calibration
Register	Function
FELNA.LBH[3:0]	LNA bias High-Band
FELNA.LBL[3:0]	LNA bias Low-Band
FEBT.RTN2[1:0]	Resistor tuning
FEBT.CTN2[1:0]	Capacitor tuning

The RF front-end registers mentioned in the following table include application-specific settings. For each application, the settings are controlled by EEPROM registers. The configuration tool must be used to calculate these EEPROM settings.

Table 3-9. RF Front-End Registers Used for Application Settings
Register	Function
FECR.ADHS	Analog-to-digital converter high sample rate
FECR.S4N3	Select 433 MHz not 315 MHz band
FECR.LBNHB	Select Low-Band not High-Band