MASKING WITHIN A DATA PROCESSING SYSTEM HAVING APPLICABILITY FOR A DEVELOPMENT INTERFACE

In current real-time debug systems, debug messages are transmitted through a limited bandwidth port ( 18 ) from an integrated circuit ( 10 ) to an external development system ( 25 ). As some integrated circuits ( 10 ) become even more densely packed with multiple bus masters ( 11, 12 ) and/or multiple busses ( 16 ) capable of generating messages, it is becoming more and more difficult for the limited bandwidth port ( 18 ) to sufficiently support the volume of debug messages that are to be transmitted from an integrated circuit ( 10 ) to an external development system ( 25 ). A plurality of masks ( 70, 80, 90, 100, 110, 120, 130, 140, 150 ) and masking circuitry ( 36 ) may be used to selectively mask portions ( 41 - 45, 51 - 55 ) of debug messages ( 40, 50 ) in order to significantly improve bandwidth.