Interfaces and Connectors
EBX-41 Reference Manual
40
Digital I/O
The 40-pin I/O connector (J21) incorporates 32 digital I/O lines. Table 19 shows the function of
each pin. The digital I/O lines are controlled using the SPI registers. See "SPI Registers" for a
complete description of the registers.
The digital lines are grouped into two banks of 16-bit bi-directional ports. The direction of each
8-bit port is controlled by software. The digital I/O lines power up in the input mode. The 24 mA
source/sink drive and short protected outputs are an excellent choice for industrial LVTTL
interfacing. All I/O pins use +3.3V signaling.
Warning!
Damage may occur if the I/O pins are connected to +5V logic.
Table 19: J21 I/O Connector Pinout
J21
Pin
Signal
VL-CBR-4004
Connector
VL-CBR-4004
Pin (Silkscreen)
1
Digital I/O 1
J1
5 (IO1)
2
Digital I/O 2
4 (IO2)
3
Digital I/O 3
3 (IO3)
4
Digital I/O 4
2 (IO4)
5
Ground
1 (GND1)
6
Digital I/O 5
J2
5 (IO5)
7
Digital I/O 6
4 (IO6)
8
Digital I/O 7
3 (IO7)
9
Digital I/O 8
2 (IO8)
10
Ground
1 (GND1)
11
Digital I/O 9
J3
5 (IO9)
12
Digital I/O 10
4 (IO10)
13
Digital I/O 11
3 (IO11)
14
Digital I/O 12
2 (IO12)
15
Ground
1 (GND2)
16
Digital I/O 13
J4
5 (IO13)
17
Digital I/O 14
4 (IO14)
18
Digital I/O 15
3 (IO15)
19
Digital I/O 16
2 (IO16)
20
Ground
1 (GND2)
21
Digital I/O 17
J6
1 (IO17)
22
Digital I/O 18
2 (IO18)
23
Digital I/O 19
3 (IO19)
24
Digital I/O 20
4 (IO20)
25
Ground
5 (GND3/PBRST#)
26
Digital I/O 21
J7
1 (IO21)
27
Digital I/O 22
2 (IO22)
28
Digital I/O 23
3 (IO23)
29
Digital I/O 24
4 (IO24)
30
Ground
5 (GND3)
31
Digital I/O 25
J8
1 (IO25)
32
Digital I/O 26
2 (IO26)
33
Digital I/O 27
3 (IO27)
34
Digital I/O 28
4 (I028)
35
Ground
5 (GND4)
36
Digital I/O 29
J9
1 (IO29)
37
Digital I/O 30
2 (IO30)
38
Digital I/O 31
3 (IO31)
39
Digital I/O 32
4 (IO32)
40
Ground
5 (GND4)
