Chapter 11 Coprocessing and Multiprocessing

The 80386 has two levels of support for multiple parallel processing units:

• A highly specialized interface for very closely coupled processors of

       a type known as coprocessors.
  

• A more general interface for more loosely coupled processors of

       unspecified type.
  

• 11.1 Coprocessing
• 11.1.1 Coprocessor Identification
• 11.1.2 ESC and WAIT Instructions
• 11.1.3 EM and MP Flags
• 11.1.4 The Task-Switched Flag
• 11.1.5 Coprocessor Exceptions
• 11.1.5.1 Interrupt 7 -- Coprocessor Not Available
• 11.1.5.2 Interrupt 9 -- Coprocessor Segment Overrun
• 11.1.5.3 Interrupt 16 -- Coprocessor Error
• 11.2 General Multiprocessing
• 11.2.1 LOCK and the LOCK# Signal
• 11.2.2 Automatic Locking
• 11.2.3 Cache Considerations