/** * Opcode #0xFE. * * CP n * * @param Core $core */ public static function opcode254(Core $core) { $dirtySum = $core->registerA - $core->memoryRead($core->programCounter); $core->FHalfCarry = ($core->unsbtub($dirtySum) & 0xf) > ($core->registerA & 0xf); $core->FCarry = $dirtySum < 0; $core->FZero = $dirtySum == 0; $core->programCounter = $core->programCounter + 1 & 0xffff; $core->FSubtract = true; }