The invention relates to a method for communicating between at least one first system (2) and at least one second system (3) via a full-duplex synchronous serial link (4) capable of simultaneously routing data between said systems (2, 3), said data comprising: at least one message (12; 43) from the first system (2) to the second system (3), at least one message (16; 45) from the second system (3) to the first system (2), and a clock signal (13; 44). According to the method: the second system (3) receives a message (12; 43) and a clock signal (13; 44) sent by the first system (2), delayed and substantially in phase; the second system (3) sends the first system (2) a message (16; 45); the clock signal (13; 44) received by the second system (3) is returned (17; 46) to the first system (2) along with the message (16; 45) sent by the second system (3); and the first system (2) receives the message (16; 45) sent by the second system (3) and the returned clock signal (17; 46), delayed and substantially in phase.