Читать книгу Microprocessor 4 - Philippe Darche - Страница 28

The memory-to-memory transfer functionality is possible in a von Neumann- inspired MPU, but it should be seen as exceptional. This is the continuity of the tendency of CISC processors to implement high-level functionalities in the material. Intel calls this mode “string addressing” for its 8086. It involves addressing the characters of a string, that is, of an array of characters by indirection using both its pointer registers SI (Source Index) and DI (Destination Index). It makes it possible, among other things, to read or write a character and, whether the repeat prefix is conditional or not, to make a copy of it in the main memory. The search function in a string is also available.