Module irq 

Interrupt request lines: which trit of the interrupt masks each device owns.

An interrupt request, conventionally shortened to IRQ, is a device asking the processor for attention. Ternaria gives each device one trit, in two control registers the processor holds:

• ip, interrupt pending. Written by the hardware. Trit k is positive while device k is asking. A device keeps asking until something attends to it, so the trit stays positive; it is a level, not a pulse.
• ie, interrupt enable. Written by the operating system. Trit k is positive while the operating system is willing to be interrupted by device k.

A source fires when both trits are positive, which is the per-trit minimum of the two masks: Kleene AND (D-06).

Why the numbering lives here

A bus fills this mask in and a processor reads it, and the two are separate crates that must agree on what each trit means. Neither can own the numbering without the other duplicating it, so it belongs to the trait they meet at, next to Addressable::interrupts.

Constants

CONSOLE

The console has input waiting.

COUNT

How many sources are defined.

TIMER

The timer reached its compare value.

Functions

mask

The value that enables one source when written to ie.