Abstract: A pair of In-Circuit-Emulator modules are embedded within a microprocessor to implement parts of an In-Circuit-Emulator system. A first In-Circuit-Emulator module, the In-Circuit-Emulator memory mapping module, maps specified physical addresses into a debug memory. The physical addresses mapped into the debug memory are set by programmable registers. The second In-Circuit-Emulator module, the In-Circuit-Emulator breakpoint module, allows the user to set conditions that cause the processor to recognize specific bus events. The In-Circuit-Emulator breakpoint module monitors an internal bus and an internal bus controller. The user can set specific bus event conditions by writing to a set of breakpoint registers in the breakpoint module.

Abstract: An in-circuit emulator trace bus clocking mechanism. A synchronization clock associated with the trace bus is provided. Arrival of a first event on a microprocessor bus to be traced is signified by a transition of a control line. A start of cycle event is detected. A start of cycle signal is generated with respect to the start of cycle event. A two stage pipeline having stage 1 storage elements and stage 2 storage elements are connected to receive data from the microprocessor bus. The start of cycle signal is used to sample data from the microprocessor bus into the stage 1 storage elements. An end of cycle event is detected. An end of cycle signal is generated with reference to the end of cycle event. The end of cycle signal is used to sample data from the stage 1 storage elements into the stage 2 storage elements. The end of cycle signal is also used to sample data appearing on the microprocessor bus at the end of the cycle into the stage 2 storage elements.