Patent ID: 7215774
Filing Date: 2007-05-08
Classification: H04H,H04N

Abstract:
1. A control system for transfer of scrambled video data through an arbitrated access common bus line, comprising: a scrambling key memory for storing a current scrambling key; a descrambling key memory; a new scrambling key generator for generating a new scrambling key, storing said new scrambling key in said descrambling key memory, and transmitting a copy of said new scrambling key through the arbitrated common data bus; a vertical sync detector for detecting a vertical sync signal in a video data and generating a sync detect signal in response; a scrambling key update controller for receiving said copy of said new scrambling key from said arbitrated common data bus and, in response to said sync detect signal, updating said current scrambling key in said scrambling key memory according to said received copy of said new scrambling key; a scrambler for scrambling said video data using the current scrambling key, updated corresponding to said vertical sync by said scrambling key update controller, to produce scrambled video data, and transmitting said scrambled video data through said arbitrated common data bus; and a descrambler for descrambling the scrambled video data received through said arbitrated common data bus based on the new scrambling key stored in said descrambling key memory to produce an unscrambled form of said video data.