* wz = an internal 16-bit register connected to 16-bit operations
* tmp, tmp2 = temporary storage whose value is thrown away after each instruction
M-Cycle Sequences have been deducted logically and verified on real hardware. See [https://baltazarstudios.com/zilog-z80-undocumented-behavior/ Arduino Z80 dongle bus activity dump].
=== Load group ===