6 power on configuration – CyberResearch PCIDIO 48H User Manual
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• Operation Theorem
Control
Word
D
4
D
3
D
1
D
0
PORT
A
PORT C
UPPER
PORT
B
PORT C
LOWER
00H
0
0
0
0
O/P
O/P
O/P
O/P
01H
0
0
0
1
O/P
O/P
O/P
I/P
02H
0
0
1
0
O/P
O/P
I/P
O/P
03H
0
0
1
1
O/P
O/P
I/P
I/P
08H
0
1
0
0
O/P
I/P
O/P
O/P
09H
0
1
0
1
O/P
I/P
O/P
I/P
0AH
0
1
1
0
O/P
I/P
I/P
O/P
0BH
0
1
1
1
O/P
I/P
I/P
I/P
10H
1
0
0
0
I/P
O/P
O/P
O/P
11H
1
0
0
1
I/P
O/P
O/P
I/P
12H
1
0
1
0
I/P
O/P
I/P
O/P
13H
1
0
1
1
I/P
O/P
I/P
I/P
18H
1
1
0
0
I/P
I/P
O/P
O/P
19H
1
1
0
1
I/P
I/P
O/P
I/P
1AH
1
1
1
0
I/P
I/P
I/P
O/P
1BH*
1
1
1
1
I/P
I/P
I/P
I/P
Table 4.2 Summary of control word (D0 - D4)
(* power on default configuration)
4.1.6 Power on Configuration
The default configuration after power on, hardware reset or software reset
sets all ports as input ports, and therefore, users don’t have to worry about
damaging the external devices when system is power on. In addition, the
default signal level can be pulled high or pulled low by setting the jumpers.
Refer to section 2.7 for setting the power on status of the DIO ports.
4.1.7 Note for Output Data
Be careful of the initial condition of digital output signals. If users set the
control word as output port after power on, the previous uncertain output
value will be put on the output pins immediately. Therefore, BE SURE TO
WRITE A SAFE VALUE TO THE PORTS BEFORE CONFIGURING THEM AS
OUTPUT PORTS.