Sam4s ER-390 SERIES Service Manual page 33

6-1 Semiconductor Base Diagram
6-1-4 Other ICs
82C55A (PLCC)
6 5 4
CS
7
GND
8
A1 9
A0 10
PC7 11
NC
12
13
PC6
PC5 14
PC4 15
16
PC0
17
PC1
18 19 20
SAM4S ER-390 SERIES
Figure 6-8 Motor Driver LB1838 Specification
TOP VIEW
3 2 1 44 43 42 41 40
39 RESET
38 D0
37 D1
36 D2
D3
35
NC
34
D4
33
D5
32
D6
31
D7
30
V
29
CC
21 22 23 24 25 26 27 28
Figure 6-9 82C55A Specification
Figure 6-10 RS-232 Transceiver MAX232
T ruth T able
IN 1, 2 ENA 1, 2
L H
H H
L L
H L
A1 A0 RD
0 0 0
0 1 0
1 0 0
1 1 0
0 0 1
0 1 1
1 0 1
1 1 1
X X X
X X 1
C1+
V
1
16
CC
V+
GND
2
15
C1- T1OUT
3
14
MAX202E
C2+ R1IN
4 13
MAX232E
R1OUT
C2- 5
12
V-
T1IN
6 11
T2OUT T2IN
7 10
9 R2OUT
R2IN 8
OUT 1, 3 OUT 2, 4
H L
L H
OFF OFF
OFF OFF
82C55A BASIC OPERATION
INPUT OPERATION
WR CS (READ)
Port A → Data Bus
1 0
Port B → Data Bus
1 0
Port C → Data Bus
1 0
Control Word → Data Bus
1 0
OUTPUT OPERATION
(WRITE)
Data Bus → Port A
0 0
Data Bus → Port B
0 0
Data Bus → Port C
0 0
Data Bus → Control
0 0
DISABLE FUNCTION
Data Bus → Three-State
X 1
Data Bus → Three-State
1 0
6 Reference Information
M ode
F orward
R everse
S tandby
S tandby
6-5