B.8.1. Breakpoint with Prefetch Abort

When a breakpointed instruction fetch causes a Prefetch Abort, the abort is taken and the breakpoint is disregarded. Normally, Prefetch Aborts occur when, for example, an access is made to a virtual address that does not physically exist, and the returned data is therefore invalid. In such a case, the normal action of the operating system is to swap in the page of memory, and to return to the previously invalid address. This time, when the instruction is fetched, and providing the breakpoint is activated (it might be data-dependent), the ARM7EJ-S processor enters debug state.

The Prefetch Abort, therefore, takes higher priority than the breakpoint.

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