A CEC block termination function, operated by a manipulating switch including at least one HDMI-CEC input port and at least two HDMI-CEC output ports, enables the manipulating switch to receive a CEC block which was initiated by a device, optionally acknowledge (ACK) the block, modify the received block, and supply the modified block to one or more devices. Optionally, a section of the CEC block may be modified, the entire CEC block may be modified, or the CEC message may be partially or completely modified.