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Signal Descriptions
Chapter 5
AMD-K6-2E+ Embedded Processor Data Sheet
23542A/0—September 2000
Preliminary Information
5.30
INTR (Maskable Interrupt)
Pin Attribute
Input
Summary
INTR is the system’s maskable interrupt input to the processor.
When the processor samples and recognizes INTR asserted, the
processor executes a pair of interrupt acknowledge bus cycles
and then jumps to the interrupt service routine specified by the
interrupt number that was returned during the interrupt
acknowledge sequence. The processor only recognizes INTR if
the interrupt flag (IF) in the EFLAGS register equals 1.
Sampled
The processor samples INTR as a level-sensitive input on every
clock edge, but the interrupt request is not recognized until the
next instruction boundary. The system logic can drive INTR
either synchronously or asynchronously. If it is asserted
asynchronously, it must be asserted for a minimum pulse width
of two clocks. In order to be recognized, INTR must remain
asserted until an interrupt acknowledge sequence is complete.
5.31
INV (Invalidation Request)
Pin Attribute
Input
Summary
During an inquire cycle, the state of INV determines whether
an addressed cache line that is found in the processor’s L1
and/or L2 caches transitions to the invalid state or the shared
state.
If INV is sampled asserted during an inquire cycle, the
processor transitions the cache line (if found) to the invalid
state, regardless of its previous state. If INV is sampled negated
during an inquire cycle, the processor transitions the cache line
(if found) to the shared state. In either case, if the cache line is
found in the modified state, the processor writes it back to
memory before changing its state.
Sampled
INV is sampled on the clock edge on which EADS# is sampled
asserted.