AMD-K6-2E/400AFR AMD [Advanced Micro Devices], AMD-K6-2E/400AFR Datasheet - Page 232

• Manufacturer Part Number: AMD-K6-2E/400AFR
• Manufacturer: AMD [Advanced Micro Devices]

AMD-K6™-2E Processor Data Sheet
214
IGNNE# is used by the external hardware to control the effect
of an unmasked floating-point exception. Under certain
circumstances, if IGNNE# is sampled asserted, the processor
ignores the floating-point exception.
Figure 80 illustrates an implementation of external logic for
supporting floating-point exceptions. The following example
explains the operation of the external logic in Figure 80:
1. As the result of a floating-point exception, the processor
2. The assertion of FERR# and the sampling of IGNNE#
3. The assertion of FERR# leads to the assertion of INTR by
4. The processor acknowledges the interrupt and jumps to the
5. When IGNNE# is sampled asserted, the processor ignores
6. When the processor negates FERR#, the external logic
See “FERR# (Floating-Point Error)” on page 103 and “IGNNE#
(Ignore Numeric Exception)” on page 108 for more details.
Floating-Point and Multimedia Execution Units
asserts FERR#.
negated indicates the processor has stopped instruction
execution and is waiting for an interrupt.
the interrupt controller.
corresponding interrupt service routine in which an I/O
write cycle to address port F0h leads to the assertion of
IGNNE#.
the floating-point exception and continues instruction
execution.
negates IGNNE#.
Preliminary Information
22529B/0—January 2000
Chapter 10