Page 84 - slides.dvi

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Can
4.
3.
2.
–
–
–
1.
–
1.
Operating
–
–
–
service
Then
for
for
split
save
Question:
enter
Systems
signal
interrupt
invoke
clear
request
—
establish
DMA
transfer
more
any
I/O
who
a
routine:
demultiplex
interrupt
is
handler
acknowledge
scheduler
data.
another
programmed
Interrupt-Driven
interrupt
Subsystem
device:
or
waiting
appropriate
registers
service
implementation
language
I/O
interrupt
I/O
in
scheduling
transfer.
transfer
into
return.
if
routine
interrupt
device:
(sometimes
processes.
who?
a
there
software.
environment
low-level
side
service
are
(processor-dependent)
(e.g.
any
a
effect
may:
C
routine
(device-specific
interrupt
of
more
but
tx).
(ISR)
I/O
not
run-time
handler
plus
stack)
requests
pending
per-device
processor-specific)
on
will:
device.
interrupt
80