Transmission of data over a serial link based on a unidirectional clock signal is provided. A unidirectional clock signal is generated based on a first clock of a master device. The unidirectional clock signal is sent to a slave device that is connected to the serial link. The master device transmits data to the slave device over the serial link based on the first clock. The slave device receives the unidirectional clock signal from a master device. The slave device transmits data over the serial link to the master device based on the unidirectional clock signal.