inter
8243
MCS-48™
INPUT/OUTPUT
EXPANDER
• Low Cost
• Simple Interface
to
MCS-48
T1
' Micro-
computers
• Four 4-Bit
I/O
Ports
• AND and OR Directly
to
Ports
• 24-Pln DIP
• Single
5V
Supply
•
High Output Drive
• Direct Extension of Resident 8048
I/O
Ports
The
Inele
8243 is an input/output expander designed specifically to provide a low cost means
of
1/0 expansion
for
the
M£S-48"
family of single chip microcomputers. Fabricated in 5 volts NMOS, the 8243 combines
low
cost, single supply
voltage
and high drive current capability.
The 8243 consists
of
four
4-bit bidirectional static
110
ports and one 4-bit port which serves
as
an
interface to the MCS-48
microcomputers. The 4-bit interface requires that only 4 1/0 lines
of
the
8048
be used
for
1/0 expansion, and also allows
multiple
8243's
to
be added
to
the same bus.
The
1/0 ports of the 8243 serve
as
a direct extension of the resident
ilO
facilities of the MCS-48 microcomputers and are
accessed by their own
MOV, ANL, and ORL instructions.
PIN
CONFIGURATION
BLOCK
DIAGRAM
PORT4
P60
vee
P40
P51
HI
P52
N2
P63
1'43
P60
PORT 5
~
P51
MOG
P52
PORT 2
P23
P53
P22
P73
P21
P72
P20
P71
PORTa
GND
P70
PORT7
6-57
AFN-00214A~1