.::External Memory::.

  • The Pentium uses an interrupt system for dealing with external memory.
  • There is a single Interrupt Request line connected to the dcontrol unit (INTR).
  • There is a single Interrupt Acknowledge line connected to the control unit (INTA).
  • These lines connect to an interrupt arbiter which is independent from the CPU.
  • The arbiters decide which device has more priority and which device connects to the CPU.
  • With one arbiter the Pentium can house up to 8 external devices.
  • With nesting the arbiters the Pentium can house up to 64 external devices.