User Manual

SPI Interface
The radio module is often used as a SPI slave to another application processor. In
this case, the following connections must be made from the radio to the AP:
Signal Interface Connector
Pin 3 (P1.2 SPI1_SS) – SPI slave select aka Chip Select. Input to radio. CS must
be asserted before each packet, and must be negated between packets.
Pin 5 (P1.3 SPI1_SPCK) – SPI clock. Input to radio.
Pin 6 (P1.5 SPI1_MOSI) – SPI Master out, slave in. Input to radio.
Pin 7 (P1.7) – Radio Attention. Output from radio. Set when the radio has a
packet waiting for the host, and will be set after the host asserts CS to indicate the
radio is ready for the transfer to begin.
Pin 8 (P1.4 SPI1_MISO) – SPI Master In, slave out. Output from radio.
AUX Connector
Pin 4 (P0.6) – Radio Wakeup. Input to radio. Must be set at least xxms before
CS is asserted. Radio will not go to sleep when this is asserted low. Only for
sleeping nodes.