| Miscellaneous functions | |
| __insert_opcode | Insert an instruction into code |
| __no_operation | Insert a NOP instruction into code |
| Data manipulation | |
| __swap_bytes | Swap bytes within a word |
| __swap_nibbles | Swap nibbles within a byte |
| Status register manipulation functions | |
| __disable_interrupt | Disable interrupts and return previous enable state |
| __enable_interrupt | Enable interrupts and return previous enable state |
| __restore_interrupt | Restore interrupt enable flag state |