System and method for collecting trace data in main storage

Abstract

A memory controller used to manage the memory interface (main store interface) for processor and input and output (I/O) device access, includes a trace array used for accumulating trace data signals to be stored to main store, control logic used to determine when the array should be updated and when its contents should be stored to main store, an address register which provides the starting address of main store assigned to store trace data, an offset address register which identifies the current address to store trace data, and a space size register used to identify the amount of main store reserved to store trace data. In a first implementation, the contents of the trace array are moved to main store when the trace array becomes full. An alternative implementation provides additional control registers and logic which allow memory to be updated from the trace array when the memory interface is not busy.