AVR not yet working, performing low level SWIM operations will require
decent amount of core specific code due to differences in pin driver
styles, timers, cycles per instruction, etc. The fact that SWIM pin
changes based on the board ADDR0, DATA0, EXP0, etc multiplies this low
level code... Thinking about executing SWIM low level drivers from SRAM.
Initialization could include loading these routines to SRAM.
For now just focusing on supporting SWIM on STM cores for SNES boards.
6eb0570335