Specifications
INTERRUPTS
The
MC68000
uP
on
the
DPM
has
7
levels
of
interrupt.
Level
7,
the
hiShest
level
is
non-maskable.
Interrupt
vector
addresses
are
fixed.
The
7
levels
of
interrupt
are:
level
7 =
BBA
non-existent
memory.
Set
when
the
BBA
tries
to
address
non-existent
memor~
in
the
VAX
cpu.
Cleared
by
clearins
the
BBA
'So'
bit.<
the
BBA
will
then
clear
its
memor~
reauest,
which
will
clear
the
LEVEL 7
interrupt.
level
6 = VERTICAL SYNC.
used
as
a
watchdos
timer.
Set
by
VERT. SYNC.
from
the
CRT
controller.
Cleared
b~
RESET
SIX.
(read
from
address
8000EO
(HEX)
level
5 = LINK
TRANSITION.
indicates
that
the
Fiber
Optic
link
has
had
either
LINK
ERROR
asserted,
or
that
LINK AVAILABLE
has
chanSed
states.
Cleared
by
either
a
power-up
reset
(hardware)
or
a
read
from
address
800040
(HEX)
level
4 =
BBA
DONE.
Used
to
indicate
that
the
BBA
has
completed
an
operation.
Cleared
by
the
BBA
when
the
68000
uP
clears
the
BBA
'So'
bit
level
3 =
Tablet
USART
interrupt.
Receiver
bu~fer
full,or
transmitter
buffer
empty.
level
2 =
Ke~board
USART
interrupt.
Receiver
buffer
full,or
transmitter
buffer
empty.
level
1 =
not
used
MANUFACTURING
MODE
A
Jumper
has
been
provided
on
the
DPM
module
that
will
allow
for
a
dynamic
functional
burn-in
of
the
zebra/bba/fotr
in
a
manufacturins
environment.
This
Jumper
reauires
the
use
of
loopback
connectors
on
the
tablet
ilo
port
(DEC.
PTt
12-15536-00),and
a
loopback
connector
on
the
ke~board
port
(DEC.PTt
12-XXXXX-XX).
when
in
this
mode,the
micro-diaSnostics
will
loop
continuouslY
on
the
power-up
self
test.
The
unit
will
halt
at
the
first
occurance
of
a
detected
error,
and
display
the
test
number
in
the
led
indicators.