External Program Memory - Intel MCS48 User Manual

APPLICATION
EXAMPLES
40 26 20
V(X
Vqd
Vjs
XTAL
1
8049
8048
8748
8035*
8039*
ALE PSEN PROG WR RD
P10
P11
P12
P13
P14
P15
P16
P17
P20
P21
P22
P23
P24
P25
P26
P27
DBO
DB1
DB2
DB3
DB4
DB5
DB6
DB7
*EA
= 5V
FOR
8035/8039
Vcc
GND
8212
LATCH
Dh
DOi
Dl
2
D0
2
Dl
3
DO3
DU
DO4
Dl
5
D0
5
Dl
6
D0
6
DI7
DO7
Dl
8
D0
8
CLR
DS
2
MD
DS,
13
or
19
21
Vdd
V
b b
Vss
8708
1Kx
8
EPROM
8212
serves as
address
latch
Address
is
valid
while
ALE
is
high
and
is
latched
when ALE
goes
low
EXTERNAL PROGRAM MEMORY
5-7