Overlay Managers; Breakpoints On Overlays - Analog Devices VisualDSP++ 3.5 Manual

Memory Overlays and Advanced LDF Commands

Overlay Managers

An overlay manager is a user-definable routine responsible for loading a
referenced overlay function or data buffer into internal memory (run-time
space). This task is accomplished with linker-generated constants and
commands.
PLIT{}
Linker-generated constants inform the overlay manager of the overlay's
live address, where the overlay resides for execution, and the number of
words in the overlay.
requested overlay and the run-time address of the referenced symbol.
An overlay manager's main objective is to transfer overlays to a run-time
location when required. Overlay managers may also:
• Set up a stack to store register values
• Check whether a referenced symbol has already been transferred
into its run-time space as a result of a previous reference
If the overlay is already in internal memory, the overlay transfer is
bypassed and execution of the overlay routine begins immediately.
• Load an overlay while executing a function from a second overlay
(or a non-overlay function)
You may require an overlay manager to perform other specialized tasks to
satisfy the special needs of a given application. Overlay managers for
Blackfin processors must be developed by the user.

Breakpoints on Overlays

The debugger relies on the presence of the
bols to support breakpoints on overlays.The symbol manager will set a
silent breakpoint at each symbol.
VisualDSP++ 3.5 Linker and Utilities Manual
for 16-Bit Processors
commands inform the overlay manager of the
PLIT{}
and
__ov_start __ov_end
sym-
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