Product Specs

Table Of Contents
23 RADIO 2.4 GHz Radio
Page
213
interval as specified in the TIFS register as long as TIFS is not specified to be shorter than the RADIO’s turn-
around time, i.e. the time needed to switch off the receiver, and switch back on the transmitter.
TIFS is only enforced if END_DISABLE and DISABLED_TXEN or END_DISABLE and DISABLED_RXEN
shortcuts are enabled. TIFS is only qualified for use in BLE_1MBIT mode, and default ramp-up mode.
23.12 Device address match
The device address match feature is tailored for address white listing in a Bluetooth Smart and similar
implementations.
This feature enables on-the-fly device address matching while receiving a packet on air. This feature only
works in receive mode and as long as RADIO is configured for little endian, see PCNF1.ENDIAN.
The Device Address match unit assumes that the 48 first bits of the payload is the device address and that
bit number 6 in S0 is the TxAdd bit. See the Bluetooth Core Specification for more information about device
addresses, TxAdd and whitelisting.
The RADIO is able to listen for eight different device addresses at the same time. These addresses are
specified in a DAB/DAP register pair, one pair per address, in addition to a TxAdd bit configured in the
DACNF register. The DAB register specifies the 32 least significant bits of the device address, while the DAP
register specifies the 16 most significant bits of the device address.
Each of the device addresses can be individually included or excluded from the matching mechanism. This is
configured in the DACNF register.
23.13 Bit counter
The RADIO implements a simple counter that can be configured to generate an event after a specific number
of bits have been transmitted or received.
By using shortcuts, this counter can be started from different events generated by the RADIO and hence
count relative to these.
The bit counter is started by triggering the BCSTART task, and stopped by triggering the BCSTOP task.
A BCMATCH event will be generated when the bit counter has counted the number of bits specified in the
BCC register. The bit counter will continue to count bits until the DISABLED event is generated or until the
BCSTOP task is triggered. The CPU can therefore, after a BCMATCH event, reconfigure the BCC value for
new BCMATCH events within the same packet.
The bit counter can only be started after the RADIO has received the ADDRESS event.
The bit counter will stop and reset on BCSTOP, STOP, END and DISABLE tasks.
The figure below illustrates how the bit counter can be used to generate a BCMATCH event in the beginning
of the packet payload, and again generate a second BCMATCH event after sending 2 bytes (16 bits) of the
payload.