Datasheet

MRF49XA
DS70590C-page 62 Preliminary © 2009-2011 Microchip Technology Inc.
From PMCREG, the following points are applicable
when using the bit functionalities:
The chip enters Receive mode if both the TXCEN
and RXCEN bits are set.
FSK/DATA/FSEL
input is equipped with an internal
pull-up resistor. To achieve minimum current
consumption, do not pull this input to logic low in
Sleep mode.
To enable the RF synthesizer, the crystal oscillator
must be turned on.
To turn on the baseband circuits, the RF
synthesizer and the crystal oscillator must be
enabled.
Setting the RXCEN bit automatically turns on the
crystal oscillator, synthesizer, baseband circuits
and RF front end.
Setting the TXCEN bit automatically turns on the
crystal oscillator, synthesizer and RF power
amplifier.
The clock tail and automatic crystal enable/disable
features help in reducing the power consumption and
are discussed in detail in Section 3.4, Crystal
Oscillator and Clock Output.
The registers associated with power management are:
•STSREG (see Register 2-1)
GENCREG (see Register 2-2)
RXCREG (see Register 2-7)
PMCREG (see Register 2-13)