PEP CP380, Руководство пользователя

Страница: 20 / 68

CP380 Introduction
ID 19313, Rev. 0100 Page 1 - 10 ® PEP Modular Computers GmbH
Figure 1-6: CP380-I/O Functional Block Diagram
1.7 General Notes
1.7.1 Modes of Operation
The CP380 uses an 8255 compatible PIO device. The operational modes of the device
are described in the following chapters. For further information on the 8255 device con-
sult the manufacturer’s data sheet.
1.7.1.1 CP380-I
The CP 380-I uses 2 operational modes of the 8255 device which are configured by
software.
Operation without Interrupt: 18 digital inputs
In this operation mode data input can be performed. The data is read in from the chosen
port and no handshaking is required. By configuring the 8255 PIO device for mode 0
operation, two ports (port A and B, both 8 bits wide) and one port (PC2 and PC4, 2 bits
wide) are available for data input.
!
Important!:
The external connections to the board should only be made in a
powered down state.
1
5
-P
in
D
S
U
B
M
a
le
Optocoupler
Optocoupler
Optocoupler
P
IO
8
2
5
5
A
V+ V-
V-
V-
8
8
2
8
8
2
PA
PB
PC
1
5
-P
in
D
S
U
B
M
a
le
B
U
S
I
n
te
rf
a
c
e
L
o
g
ic
C
P
C
I
IN
T
E
R
F
A
C
E