Syntax:
#option removeAVRvectors
Explanation:
#option removeAVRvectors reduces the AVR interrupt vector table (IVR) in the compiled output to the smallest possible size, saving flash memory.
Normally, AVR flash memory begins with the full interrupt vector table — a fixed block of addresses, one per interrupt source, that the processor jumps to when an interrupt occurs. The actual user code is placed in memory after this entire table. On devices with many interrupt sources this table can occupy a significant amount of flash, much of which is typically unused.
When #option removeAVRvectors is used, the compiler determines which interrupt vectors are actually used in the program and writes only those entries,
up to and including the highest used vector address. User code is then placed immediately after the last required vector entry.
If no interrupts are used at all, the vector table is omitted entirely and user code starts at address 1, immediately after
the reset vector.
ON INTERRUPT can be used with #option removeAVRvectors. The compiler will preserve the vector entries required by any interrupts that are defined in the program.
Restriction:
Inline ASM code that uses or references interrupt vectors directly must not be used when this directive is active, as the full vector table will not be present in the compiled output.
Example:
#option removeAVRvectors
