Program Counter in AArch32 state
You can use the Program Counter explicitly, for example in some T32 data processing instructions, and implicitly, for example in branch instructions.
The Program Counter (PC) is accessed as PC (or R15). It is incremented by the size of the instruction executed, which is always four bytes in A32 state. Branch instructions load the destination address into the PC. You can also load the PC directly using data operation instructions. For example, to branch to the address in a general purpose register, use:
During execution, the PC does not contain the address of the currently executing instruction. The address of the currently executing instruction is typically PC-8 for A32, or PC-4 for T32.
NoteARM® recommends you use the
BXinstruction to jump to an address or to return from a function, rather than writing to the PC directly.