Measurement Computing PC-CARD-DIO48 - Manual (Page 7)

Chapter 1
Introducing the PC-CARD-DIO48
Overview: PC-CARD-DIO48 features
The PC-CARD-DIO48 is a data acquisition and control board for IBM PC compatible computers having PC-
CARD/PCMCIA type slots.
PC-CARD-DIO48 features two 82C55 digital I/O chips. The 82C55 chip uses TTL logic.
The digital I/O is organized into two 24-bit groups (24 channels per 82C55). Each 24-bit group is divided into
three ports – A, B, and C. Ports A and B are banks of 8 bits. Port C can be configured as two banks of 4 bits or
one bank of 8 bits. Each bank is programmable as input or output.
On power up and reset, all I/O bits are set to input mode. All signals pass through a 50-pin high-density
connector. The board is completely plug-and-play, with no switches or jumpers to set.
PC-CARD-DIO48 block diagram
PC-CARD-DIO48 functions are illustrated in the block diagram shown here.
82C55
82C55
Controller
FPGA
Ho
s
t B
u
s
Ad
ap
to
r
A0 (7:0)
Data Bus
Address Bus
B0 (7:0)
C0 (7:0)
A0 (7:0)
B0 (7:0)
C0 (7:0)
Cont
ro
l
2nd
2nd
2nd
Cont
ro
l
1st
1st
1st
Figure 1. PC-CARD-DIO48 functional block diagram
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