A richer approachThe very first interrupt vectors (say for instance 0 to 15) are reserved for CPU internal interrupts. One of them (probably 0) is for the Timer, the rest is for reporting Fault Conditions. Being vectors, they have priorities so at design time I would assign higher priorities to worse conditions.
As per wiring, this approach is more natural since different fault conditions come from different circuits in the form of different wires. The Interrupt Controller will be receiving these wires as internal IRQ lines.
Now, an OS handling Fault Conditions will be able to identify the origin of the failure. Still software interrupts can simulate both timer and fault interrupts by using 0 to 15 as the argument.
|
Homebuilt CPUs WebRing
JavaScript by Qirien Dhaela
Join the ring?
David Brooks, the designer of the Simplex-III homebrew computer, has founded the Homebuilt CPUs Web Ring. To join, drop David a line, mentioning your page's URL. He will then add it to the list.
You will need to copy this code fragment into your page.
|