Either Of - Intel MCS48 User Manual

8041A/8741A
PROGRAMMING,
VERIFYING,
AND
ERASING THE
874IA
EPROM
Programming/Verification
In brief,
the
programming
process
consists
of:
activat-
ing
the program mode,
applying an address,
latching the
address, applying
data,
and
applying a
programming
pulse.
Each word
is
programmed
completely before
moving on
to
the next and
is
followed by a
verification
step.
The
following
is
a
list
of the pins
used
for
program-
ming and
a description
of their functions:
Pin Function
XTAL1
Clock
input
(1
to
6
MHz)
RESET
Initialization
and address
latching
TESTO
Selection
of
program
or verify
mode
EA
Activation
of
program/verify
modes
BUS
Address and
data
input
data output during
verify
P20-1
Address
input
V
D D
Programming power
supply
PROG
Program pulse
input
The
program/verify
sequence
is:
1.
V
DD
=
5V,
clock applied
or internal oscillator
operating,
RESET =
OV,
TEST =
5V,
EA
a
5V,
BUS
and
PROG
floating.
2.
Insert 8741
A
in
programming
socket.
3.
TEST = OV
(select
program
mode).
4.
EA =
25V
(activate
program
mode).
5.
Address
applied
to
BUS
and
P20-1.
6.
RESET = 5V
(latch address).
7.
Data
applied
to
BUS.
8.
V
D
=
25V (programming
power).
9.
PROG
= OV
followed by
one
50
ms
pulse
to
25V.
10.
V
DD
=
5V.
11.
TEST = 5V
(verify
mode).
12.
Read and
verify
data
on BUS.
13.
TESTO
=
OV.
14.
RESET =
OV
and
repeat
from
step
5.
15.
Programmer
should be
at
conditions of step
1
when
8741
A
is
removed
from
socket.
Programming
Options
The
8741
A
EPROM
can be programmed
by
either of
two
Intel
products:
1.
PROMPT-48
Microcomputer Design
Aid.
2.
Universal
PROM
Programmer
(UPP-101 or
UPP-102)
Peripheral of the Intellec®
Development System
with
a
UPP-848
Personality Card.
BUS
AND PROG CAN
BE
DRIVEN
ONLY
DURING
THIS
TIME
<
ADDRESS
A
-A
7
X
<
<
ADDRESS
A
8
-A
9
>
PROG
+5V.
+0V
WARNING:
An
attempt to
program
a
missocketed 8741A
will result in
severe
damage
to
the
part.
An
indication
of
a properly socketed
part
is
the
appearance
of
the
SYNC
output.
The
lack of this
clock
may
be used
to disable the
programmer.
Figure
5.
Programming/Verification
Sequence
8-120
00188A