5.2.2
Address decode & D/I CKT
DI8
DI9
DI10
DI11
DI12
DI13
DI14
DI15
VCC
U2
74HCT244
SOL20
2
18
4
16
6
14
8
12
11
9
13
7
15
5
17
3
1
19
1A1
1Y1
1A2
1Y2
1A3
1Y3
1A4
1Y4
2A1
2Y1
2A2
2Y2
2A3
2Y3
2A4
2Y4
1G
2G
J2
CON20A
JDIP20P
FEMALE
U1
74HCT244
SOL20
1
19
2A4
2Y4
1G
2G
U3
74HCT138
SOIC16
1
2
3
6
4
5
15
14
13
12
11
10
9
7
A
B
C
G1
G2A
G2B
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
VCC=20
GND=10
VCC=16
GND=8
inportb(0)
inportb(1)
inportb(2)
inportb(3)
inportb(4)
inportb(5)
inportb(6)
inportb(7)
The CS\ will be active if program input/output from I/O address BASE+0 to
BASE+0xff.
Read DI 0 to 7
DI_0_7=inportb (BASE+0);
Read DI 8 to 15
DI_8_15=inportb (BASE+1);
The power-up default value of BASE is 0.
It is
not
recommended to change the value of BASE from 0 to another value.
I/O Expansion Bus for 7188X/7188E User’s Manual, Jan/2005 v1.5, 7PH-000-15---26