I am trying to understand what the opcode might be for SUB when using 8-bit AVR. I have this to look up in http://lyons42.com/AVR/Opcodes/A... and when I look up SUB, I get opcodes 18xx, 19xx,1Axx and 1Bxx all depending on how the registers are being mixed together. How can I understand this, does the Micro-
Controller have four opcodes for SUB: 18xx, 19xx,1Axx and 1Bxx or 18,19,1A,1B depending on what registers its being used with?
I also looked up instruction set for AVR in general http://ww1.microchip.com/downloa...
and get for SUB 16-bit opcode, but that can not be right for 8-bit controller, right?