Notes
(Cont'd)
Privileged
I
nstrucUons
4. The Special Function
must
shift
the effective address to provide
the
segment
and
page in
the
low-order position
within
each
stack
item.
The
format
of
an
address in the
stack
is as follows:
Indicators
I
SEG
I
PAGE
o
6 7 9 10
15
The seven high-order
bit
positions, when
set
(1),
indicate
the
specific
interrupt
condition
(s)
for
the
Paging
Error
Interrupt
(Priority
19)
and
Paging
Queue
Interrupt
(Priority
20) as follows:
Bit
0:
Non-privileged mode was set
(N
= 1)
and
the
control
bit
S
was
reset
(S
=
0).
Bit
1:
Either
one
or
both
of
the two unused bits
of
the
segment
field were not zero.
Bit
2:
The
Page
Control
Bit
was
set
(M =
1)
and
the
high-order
bit
of
the
Displacement field
of
the address was
set
(1).
Bit
3:
Non-privileged mode was set
(N
=
1)
and
the
direct
address
bit
is set (D =
1).
Bit
4:
Control
bit
E was
set
(E
=
1)
and a
write
operation
was
attempted to the page.
Bit
5:
Translation table element
has
control
bit
U
reset
(U
= 0)
(Le., page not utilizable).
Bit
6:
Flags
the
stack address as a Direct Address,
not
subject to
translation.
If
multiple
interrupt
conditions of different kinds occur on
the
same page,
the
page address is listed once in the address
stack
and
all applicable condition bits
are
set.
5.
This Special Function is to be used
for
analysis
of
Paging
Error
condition
or
Paging
Queue
Interrupt
condition on the normal instruc-
tion
set
of
the 70/46
and
is not usable
for
analysis
of
other
Special
Functions.
6.
This Special Function provides a maximum
of
two instruction
addresses
for
I/O
instructions.
It
does not provide the addresses
of
the
Channel Address Word
or
Channel Control Word
for
any
of
the
Paging
Error
or
Paging
Queue
Interrupt
conditions.
7.
The operand addresses provided
for
Paging
Error
condition
or
Paging
Queue
Interrupt
condition on
the
Translate
and
the
Trans-
late
and
Test instructions
are
based on the assumption
that
the
tables involved
are
maximum size (256
bytes).
In
any
case where the table is less
than
256 bytes, a false indica-
tion
of
a
Paging
Error
condition
of
Paging
Queue condition
may
have occurred,
and
the ending table address provided by
this
Special
Function
may
be incorrect.
100
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