Patent ID: 7127387

Claim:
A method of trace data compression in a trace system capable of receiving trace data on a first port and a second port comprising the steps of: storing a prior data value; if trace data is currently received on only one of the first port and the second port, then comparing respective equal length sections of said trace data currently received on the one port with the stored prior data value and generating a compression map having individual bits corresponding to said respective equal length sections, each individual bit having a first digital state if said respective equal length sections match and a second opposite digital state if said respective equal length sections do not match, transmitting data corresponding to said trace data currently received on the one port by transmitting said compression map and sections of said trace data currently received on the one port for which said corresponding bit of said compression map has said second digital state; and if trace data is currently received on both the first port and the second port, then comparing respective equal length sections of said trace data currently received on the first port with the stored prior data value and generating a first compression map having individual bits corresponding to said respective equal length section, each individual bit having a first digital state if said respective equal length sections match and a second opposite digital state if said respective equal length sections do not match, transmitting data corresponding to said trace data currently received on the first port by transmitting said first compression map and sections of said trace data currently received on the first port for which said corresponding bit of said first compression map has said second digital state; comparing respective equal length sections of said trace data currently received on the second port with said trace data currently received on the first port and generating a second compression map having individual bits corresponding to said respective equal length sections, each individual bit having a first digital state if said respective equal length sections match and a second opposite digital state if said respective equal length sections do not match, and transmitting data corresponding to said trace data currently received on the second port by transmitting said second compression map and the sections of said trace data currently received on the second port for which said corresponding bit of said second compression map has said second digital state.