Loopback-based built-in-self-test

An apparatus for self-test of a near-field communication, NFC, radio frequency, RF, front-end unit comprising one NFC antenna driver and at least one NFC unit from a group comprising a NFC reader and a NFC card emulator, the RF front-end unit being connected to a digital front-end unit, the antenna driver and the NFC unit of the RF front-end unit being interconnected through a first connection line via respective first input-output interfaces and being also interconnected through a second connection line via respective second input-output interfaces, and the digital front-end unit being connected to the second connection line, the apparatus comprising a processor configured to command:

• means for activating the NFC antenna driver and the NFC unit based on control signals received from the digital front-end through the second connection line;
• means for generating a first signal onto the first connection line by modulating a respective first bitstream sent by the digital front-end;
• means for retrieving, at the NFC unit, a second bitstream from the second connection line, by demodulating the first signal, onto the second connection line;
• and,
• means for determining an outcome of the self-test by monitoring the demodulated signal;
• wherein the NFC unit comprises both the NFC reader and the NFC card emulator, and the first signal is configured to modulate a bitstream having no useful data, the processor being further configured to command, before the activation the operation of demodulating, the first signal being further configured to modulate a third bitstream, in order to generate a second signal that emulates a signal transmitted from an external NFC card.