The runtime zeropage locations used by the compiler are declared in the assembler include file zeropage.inc.
Location | Size | Meaning | Usage |
---|---|---|---|
sp | 2 | stack pointer | access the parameter stack |
tmp1..tmp4 | 1 ea. | temporary value | can be written to at any time (caller saved) |
ptr1..ptr4 | 2 ea. | pointer | can be written to at any time (caller saved) |
sreg | 2 | secondary register | can be written to at any time (caller saved) |
regsave | 4 | register save area | can be written to at any time (caller saved) |
regbank | 6 | register bank | can be used only after saving (callee saved) |