The CC1101 has two dedicated configurablepins (GDO0 and GDO2) and one shared pin(GDO1) that can output internal statusinformation useful for control software. Thesepins can be used to generate interrupts on theMCU. See Section 30 page 54 for more detailson the signals that can be programmed.GDO1 is shared with the SO pin in the SPIinterface. The default setting for GDO1/SO is3-state output. By selecting any other of theprogramming options, the GDO1/SO pin willbecome a generic pin. When CSn is low, thepin will always function as a normal SO pin.