Method and apparatus for debugging a data processing system

A data processing system ( 10 ) includes a CPU ( 12 ) and debug circuitry ( 16 ). CPU ( 12 ) can execute instructions which provide direct input to one or more of trigger circuitry ( 32 ), multi-function debug counters ( 34 ), combining logic ( 36 ), and action select and control logic ( 38 ). Breakpoints can be cascaded, and separate breakpoint sequences can be triggered from a same trigger. A selected trigger ( 117 ) can produce a resulting action or trigger ( 119 ) but only if it occurs in a predetermined order compared to one or more other triggers ( 117 ). Multi-function debug counters ( 34 ) can perform a wide variety of programmable functions, can be started and stopped using the same or separate triggers, and can be optionally concatenated with each other.