At A Procedure Call, The Following Must Be True; At An Interrupt, The Following Must Be True; Return Values; Procedure Call And Return - Analog Devices VISUALDSP++ 3.5 Manual

At a procedure call, the following must be true:

• For the ADSP-219x DSPs, no space beyond the
• There must be at least one free slot on the
return address.

At an interrupt, the following must be true:

• Space beyond the
• For the ADSP-219x DSPs, the first 32 words beyond the
be protected; the interrupt routine should decrement the
and then restore the original value of

Return Values

Return values always use registers. Single word return values come back in
register . Double word return values are stored in
AX1
significant part in
If the return value is larger than two words, then the caller must allocate
space and pass the address in, as a "hidden argument". The register
used for this purpose.

Procedure Call and Return

To call a procedure:
1. Evaluate the arguments and push them onto the stack.
2. Call the procedure.
3. On return, remove arguments if desired.
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
for ADSP-219x DSPs
must be available.
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.
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