Patent ID: RE38898

Claim:
A method for communicating video data via a data bus between a master device and a slave device which are each coupled to said bus, comprising the steps of: transmitting from said master device to said data bus a slave address of said slave device and a command; generating, at said master device, a KEYCMD signal as a function of said command and a master security key; receiving, at said slave device from said data bus, said slave address and said command and recognizing said slave address as corresponding to said slave device; generating, at said slave device, an ACK signal as a function of said command and a slave security key; transmitting from said slave device to said data bus a master address of said master device and said ACK signal; receiving, at said master device from said data bus, said master address and said ACK signal and recognizing said master address as corresponding to said master device; comparing said KEYCMD signal generated by said master device with said ACK signal received by said master device; and executing a data transfer between said master device and said slave device if said KEYCMD signal corresponds to said ACK signal.