blah blah bullshit
register indexed addressing mode
opcode 0100
src reg 0100
ad 1
B/W 0
as 01
dest reg 0101

absolute addressing mode
opcode 0100
src reg 0100
ad 1
B/W 0
as 01
dest reg 0101

register indirect addressing mode
opcode 0100
src reg 0100
ad 0
B/W 0
as 10
dest reg 0101

reg ind autoinc
opcode 0100
src reg 0100
ad 0
B/W 0
as 11
dest reg 0101

immediate addressing mode
opcode 0100
src reg 0000
ad 0
B/W 0
as 11
dest reg 0101

instruction set
27 core inst
24 emu inst
3 core inst formats (dual op, single op, jump)
single and dual can be byte or word inst, w is default

emulated instructions are replaced by core instructions by the compiler


talking about interrupts now
RETI (return from interrupt) is the last op your ISR (interrupt service routine) should call