Digital I/O - VersaLogic Copperhead VL-EBX-41 Reference Manual

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!
EBX-41 Reference Manual
Damage may occur if the I/O pins are connected to +5V logic.
Table 19: J21 I/O Connector Pinout
J21
Pin Signal
1 Digital I/O 1
2 Digital I/O 2
3 Digital I/O 3
4 Digital I/O 4
5 Ground
6 Digital I/O 5
7 Digital I/O 6
8 Digital I/O 7
9 Digital I/O 8
10 Ground
11 Digital I/O 9
12 Digital I/O 10
13 Digital I/O 11
14 Digital I/O 12
15 Ground
16 Digital I/O 13
17 Digital I/O 14
18 Digital I/O 15
19 Digital I/O 16
20 Ground
21 Digital I/O 17
22 Digital I/O 18
23 Digital I/O 19
24 Digital I/O 20
25 Ground
26 Digital I/O 21
27 Digital I/O 22
28 Digital I/O 23
29 Digital I/O 24
30 Ground
31 Digital I/O 25
32 Digital I/O 26
33 Digital I/O 27
34 Digital I/O 28
35 Ground
36 Digital I/O 29
37 Digital I/O 30
38 Digital I/O 31
39 Digital I/O 32
40 Ground
VL-CBR-4004 VL-CBR-4004
Connector Pin (Silkscreen)
5 (IO1)
J1
4 (IO2)
3 (IO3)
2 (IO4)
1 (GND1)
J2 5 (IO5)
4 (IO6)
3 (IO7)
2 (IO8)
1 (GND1)
5 (IO9)
J3
4 (IO10)
3 (IO11)
2 (IO12)
1 (GND2)
J4 5 (IO13)
4 (IO14)
3 (IO15)
2 (IO16)
1 (GND2)
J6 1 (IO17)
2 (IO18)
3 (IO19)
4 (IO20)
5 (GND3/PBRST#)
1 (IO21)
J7
2 (IO22)
3 (IO23)
4 (IO24)
5 (GND3)
J8 1 (IO25)
2 (IO26)
3 (IO27)
4 (I028)
5 (GND4)
J9 1 (IO29)
2 (IO30)
3 (IO31)
4 (IO32)
5 (GND4)
Interfaces and Connectors
40