Table of Contents        Previous topic       Next topic       

C COMPILER->Compiler Command Line Options->Preserve Iram (/Oi)

This option is only relevant to large memory model, reentrant functions.  When a function is called from within a large memory model reentrant function, the calling function can either preserve its frame pointer on the 8051 internal stack and restore it after the function call or recalculate it.  By default the compiler will preserve it on the 8051 internal stack since it is faster and more compact.  However, this takes up valuable internal ram - 2 bytes for each function call.  The /Oi option tells the compiler to recalculate the frame point and not to save it in internal ram.