
Interfaces and Connectors
EBX-18 Hardware Reference manual
23
J4
I/O
C
ONNECTOR
The 50-pin J4 I/O connector incorporates the COM ports, PS/2 keyboard and mouse, the push-
button reset, and speaker interfaces. Table 9 provides the pinout and shows the pin orientation of
connector.
Table 9: J4 I/O Connector Pinout and Pin Orientation
Pin
Signal
Pin
Signal
1
Data Carrier Detect
(COM1)
2
Data Set Ready
(COM1)
3
Receive Data
(COM1)
4
Request to Send
(COM1)
5
Transmit Data
(COM1)
6
Clear to Send
(COM1)
7
Data Terminal Ready
(COM1)
8
Ring Indicator
(COM1)
9
Ground
(COM1)
10
Data Carrier Detect
(COM2)
11
Data Set Ready
(COM2)
12
Receive Data
(COM2)
13
Request to Send
(COM2)
14
Transmit Data
(COM2)
15
Clear to Send
(COM2)
16
Data Terminal Ready
(COM2)
17
Ring Indicator
(COM2)
18
Ground
(COM2)
19
Ground
(COM3)
20
RTS [RS-232]/
TxD+ [RS-422/485]
(COM3)
21
TXD [RS-232]/
TxD- [RS-422/485]
(COM3)
22
Ground
(COM3)
23
RXD [RS-232]/
RxD- [RS-422/485]
(COM3)
24
CTS [RS-232]/
RxD+ [RS-422/485]
(COM3)
25
Ground
(COM3)
26
Ground
(COM4)
27
RTS [RS-232]/
TxD+ [RS-422/485]
(COM4)
28
TXD [RS-232]/
TxD- [RS-422/485]
(COM4)
29
Ground
(COM4)
30
RXD [RS-232]
/RxD- [RS-422/485]
(COM4)
31
CTS [RS-232]/
RxD+ [RS-422/485]
(COM4)
32
Ground
(COM4)
33
+5V (Protected)
34
Mouse Data
35
Ground
36
Mouse Clock
37
Pushbutton Reset
38
Ground
39
Ground
40
NC
41
Ground
42
NC
43
+5V (Protected)
44
Keyboard Data
45
Ground
46
Keyboard Clock
47
+5V (Protected)
48
Programmable LED
49
+5V (Protected)
50
Speaker Drive