User`s manual

5.2.2 Address decode & D/I CKT
DI8
DI9
DI10
DI11
DI12
DI13
DI14
DI15
A0 D0 DI0
A1 D1 DI1
A2 D2 DI2
A3 D3 DI3
A4 D4 DI4
A5 D5 DI5
A6 D6 DI6
D7 DI7
WR\
CS\ RD\
VCC
U2
74HCT244
SOL20
218
416
614
812
119
137
155
173
1
19
1A11Y1
1A21Y2
1A31Y3
1A41Y4
2A12Y1
2A22Y2
2A32Y3
2A42Y4
1G
2G
J2
CON20A
JDIP20P
FEMALE
1
3
5
7
9
11
13
15
17
19
2
4
6
8
10
12
14
16
18
20
U1
74HCT244
SOL20
218
416
614
812
119
137
155
173
1
19
1A11Y1
1A21Y2
1A31Y3
1A41Y4
2A12Y1
2A22Y2
2A32Y3
2A42Y4
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, Jun/2004 v1.4, 7PH-000-14---26