Author :
Craig
Steiner
Source :
8052.com
Polling
Sequence
The 8051
automatically
evaluates
whether
an
interrupt
should
occur
after
every
instruction.
When
checking
for
interrupt
conditions,
it
checks
them in
the
following
order:
-
External
0
Interrupt
-
Timer
0
Interrupt
-
External
1
Interrupt
-
Timer
1
Interrupt
-
Serial
Interrupt
This means that if a Serial Interrupt occurs at the exact
same
instant
that an
External
0
Interrupt
occurs,
the
External
0
Interrupt
will be
executed
first
and the
Serial
Interrupt
will be
executed
once the
External
0
Interrupt
has
completed.
