Gpio Interrupts; Io_On_Interrupt - HP 9000 Series 300 Tutorials Manual

GPIO Interrupts
Series 300 computers recognize the following GPIO interrupt condition:
EIR EIR line has been asserted.
The Series 800 HP 27112 GPIO interface recognizes the following interrupt
conditions:
SIEO Status line
a
has been set.
SIEI Status line 1 has been set.
The Series 800 HP 27114 GPIO interface recognizes the following interrupt
condition:
EIR EIR line has been asserted.
io_on_interrupt
DIL provides two subroutines for controlling interrupts: io_on_interrupt and
io_interrupt_ctl. The first, io_on_interrupt, sets up interrupt conditions
and has the form:
io_on_interrupt(eid, cause_vee, handler);
where eid is the interface entity identifier for a GPIO or raw HP-IB interface.
handler points to the function that is to be invoked when the interrupt
condition occurs, and cause_ vec is a pointer to a structure of the form:
struct interrupt_struct {
int cause;
int mask;
};
The interrupt_struct structure is defined in the include file dvio. h.
cause is a bit vector specifying which selectable interrupt or fault events will
cause the handler routine to be involked Available interrupt causes are usually
specific to the type of interface being considered. In addition, certain exception
(error) conditions can be handled by the io_on_interrupt subroutine. If the
cause vector has a zero value, it, in effect, disables interrupts for that eid.
mask is an integer value that is used to define which parallel-poll response lines
are to be recognized in an HP-IB parallel poll interrupt. The value for mask
is formed from an 8-bit binary number, each bit of which corresponds to one
2-28 General-Purpose Routines