Category:68000 Assembly: Difference between revisions

Loading immediate values into address registers is different. You can only move words or longer into address registers, and if you move a word, the value is sign-extended. This means that if the top nibble of the word is 8 or greater, the value gets padded to the left with Fs, and is padded with zeroes if the top nibble is 7 or less. If you're adding a constant value less than 7FFF to an address, it's usually safe to use the word length operation, andwhich takes less bytes to encode than the long length version.