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*
Maskable
Non
Interrupt
A
negative
edge
be
generated.
sequence
by
the
and
program,
interrupt.
*
Fast-Interrupt
Request(FIRQ)
level
this
A
Low
on
its
provided
mask
the
standard
over
it
stacks
the
only
counter.
program
Request(I§Q)
*
Interrupt
level
A
Low
input
provided
the
mask
machine
it
state
provides
also
has
lower
priority
a
*
E,
Q
is
similar
E
to
theHD468OO
clock
signal
which
the
leading
of
edge
*MRDY
This
input
control
time.
access
*
DMA/BREQ
The
DMA/BREQ input
acquiring
the
MPU
dynamic
refresh.
memory
taken
off
the
bus.
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(PIA
3
Peripheral
Interface
(U
pin
arrangement
(GNDHM
PM
PM
PM
PM
PM
,As
PM
PA1
HD46821P
no
(Pm)
Pm
N215
P91
PB*
:Es
6
C82
(5\/WEE: : RM
All manuals and user guides at all-guides.com
(NMI)
this
input
requests
on
Anon-maskeble
also
has
higher
a
initiate
input
pin
will
bit(F)
in
the
CC
is_§lear.
Interrupt
Request(IRQ),and
condition
contents
of
the
this
pin
will
initiate
on
in
bit(I)
the
CC
is
slower
a
response
than
FIRQ.
bus
timing
leads
E.Address
from
Data
is
latched
Q.
signal
allows
stretching
_
fa
provides
method
of
another
bus
for
use.
When
BA
Low,
goes
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CA'
CM
WOT
%§
R50
RS,
m
0
32
D1
nz
DJ
FED#
I
05
D6
Z
Q
CSD
T2
nonmaskable
that
a
interrupt
be
cannot
priority
than
E I R Q , I R Q
fast
interrupt
a
This
sequence
is
fast
in
the
code
register
interrupt
an
Request
clear.
Since
stacks
IRQ
to
interrupt
than
is
signal
quadrature
§Z52;Q
a
the
MPU
will
be
valid
the
falling
edge
on
of
E
and
to
Q
suspending
execution
Typical
include
uses
the
device
DMA
should
*
PIA
INTERFACE
SIGNALS
_
__.
._
,___
__
_
K
FLA
aleuirectional
The
bi-directional
the
transfer
(D6'D7)allow
data
between
the
MPU
The
data
bus
output
three
devices
state
in
the
high
impedance(off)
exception
when
the
PIA
read
operation.
a
*
PIA
Enable(E)
The
enable
pulse,E,
timing
signal
that
to
the
PIA.
Timing
is
signals
referenced
and
trailing
edges
*
PIA
Read/wri§;e
This
signal
is
generated
MPU
to
control
the
interrupt
inhibited
software
o r
sequence
has
priority
that
sense
and
the
sequence
entire
the
FIRQ,IRQ
with
of
E.
extend
data
and
DMA
and
be
FOR
MPU
_
_
._
_
.
uataLD»~jU7)
Qines
data
of
and
the
PIA.
drivers
are
that
remain
state
MPU
performs
is
the
only
is
supplied
of
all
other
the
to
leading
of
the
E
pulse.
the
by
direction
of
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