15.10.1 Interrupts and CPU Stalling

The CPU cannot fetch the code from the same Flash bank, either BFM or PFM, that is the target of the programming operation. When attempting this operation, the CPU ceases to execute code (stall) while the programming operation is in progress. CPU code execution does not resume until the programming operation is complete, and, when this occurs, any pending interrupts, including those from the Flash Controller, are processed in order of priority.

Note: Code that is already loaded into the processor cache continues to execute up to the point where an attempt is made to fetch code or data from the same Flash bank as the active programming operation. At this point the CPU stops.

The user can avoid the stalling of the CPU by placing any needed executable code in SRAM during Flash programming.