10
SP338/SP339/XR34350 EVALUATION BOARD USER’S MANUAL
REV. 2.0.1
2.1.8
RS-485/422 Mixed Duplex Mode (SP338 Only)
Figure 9
below shows the SP338 configured in the full-duplex RS-485/422 mode.
?
J23 Pins 7 & 8 (MODE0) - ’1’ (jumper installed between these pins)
?
J23 Pins 9 & 10 (MODE1) - ’1’ (jumper installed between these pins)
?
J23 Pins 11 & 12 (MODE2) - ’1’ (jumper installed between these pins)
The RS-485 signals are also accessible at J16.
F
IGURE
9. RS-485/422 M
IXED
D
UPLEX
M
ODE
R2
R3
R4
R6
R7
R8
R9
TP6
TP8
TP12
TP14
TP16
TP18
TP34, TP55
TP32, TP54
TP30, TP53
TP28, TP52
TP26, TP51
TP24, TP43
TP22, TP42
TP20, TP41
Sl
ew
Di
r1
Di
r2
Mo
de
0 =
1
Mo
de
1 =
1
Mo
de
2 =
1
Ter
m
InvDi
r
En
abl
e =
1
Vc
c
L1 = 1
L2
L3
L6
L7
L8
L9
Vcc
R1
T1
R2
R3
T2
R4
R2
R3
R4
R6
R7
R8
R9
120O
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
1
2
3
4
5
6
7
8
9
10
30
29
28
27
26
25
24
23
22
21
120O
120O
120O
All pull-downs 330kO
R1
V+
C2+
Vc
c
C1+
C1-
C2-
V-
Vc
c
C3
0.1
µF
C2
0.1
µF
C1
0.1
µF
C4
0.1
µF
Cc
1.0
µF
