Patent ID: 6347368
Filing Date: 2002-02-12
Classification: G06F

Abstract:
A microcomputing device adapted to exchange data with an external device while said microcomputing device is executing an application program in run time or in single step mode, said microcomputing device comprising:a device core responsive to application program instructions and data exchange instructions, said device core including a primary program counter; at least one primary instruction bus that presents said application program instructions to said device core; at least one secondary instruction bus that presents said data exchange instructions to said device core; an instruction bus selection circuit that controls to which of said instruction buses said device core will respond; at least one data exchange external interface adapted to collectively: accept said data exchange instructions from an external device and present said data exchange instructions to said secondary instruction bus; and accept data and status information regarding data exchange from elements of said microcomputing device other than said data exchange external interface and provide said data and status information regarding data exchange to an external device; and a means for preserving and restoring contents of said primary program counter without the use of a core stack of said microcomputing device.