An example device includes a data port to provide a data channel to a host and a processor coupled to the data port. The processor includes an operational mode and a low-power mode in which the processor is to perform fewer operations than in the operational mode. The processor is to execute instructions in the operational mode and to update the instructions with updated instructions received via the data channel in the operational mode. The device further includes a side channel to receive a signal from the host to trigger the processor to switch from the low-power mode to the operational mode and to initiate update of the instructions with the updated instructions.