Analog Devices VisualDSP++ 3.5 Manual page 231

Memory Overlays and Advanced LDF Commands
Code in Non-Overlay Memory
F1:
call F2
call F3
/* PLIT & overlay manager handle
calls, using the PLIT for resolving
calls and loading overlays as needed */
.plit_F2:
.plit_F3:
/* OM: load overlay defined in setup (from .plt),
Overlay 1
Overlay 2
Runtime Overlay Memory
Figure 5-4. PLITs and Overlay Memory – Inter-Overlay Calls
The linker resolves all references to variables in overlays, and the PLIT lets
an overlay manager handle the overhead of loading and unloading
overlays.
L
Not putting global variables in overlays optimizes overlays. This
action ensures that the proper overlay is loaded before a global is
referenced.
VisualDSP++ 3.5 Linker and Utilities Manual
for 16-Bit Processors
// function F1 defined
// set up OM information
jump OM
// set up OM information
jump OM
branch to address defined in setup */
F2: // function F2 defined
call F1
call .plit_F3
F3: // function F3 defined
call F1
call .PLIT_F2
// currently loaded overlay
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