1 INTRODUCTION
The PC-CARD-DAC08 is an eight-channel, analog output control board for IBM PC
compatible computers having PCMCIA-type slots. The heart of the board is an octal,
13-bit digital-to-analog converter of which only 12 bits are used for each output.
Analog voltage signals are generated by the D/A from registers. Control of I/O
operations is done by the Field Programmable Gate Array (FPGA) on the board
(Figure 1-1). Double-buffering of the output registers permit simultaneous output
changes.
Range of the analog outputs is bipolar, ±5V.
In addition to the analog outputs, there are eight bi-directional digital I/O lines
arranged in two, 4-bit ports. They provide the capability of sensing and controlling
discrete events (via external signal-conditioning hardware). The ports can be
programmed to be either eight inputs, eight outputs, or four inputs and four outputs.
Figure 1-1. PC-CARD-DAC08 Block Diagram
1
PC
M
CIA B
U
S
C
O
N
N
EC
T
O
R P1
(68-P
IN
)
ADDRESS
BUS
HO
ST
B
U
S
A
D
A
P
T
E
R
CONTROLLER
FPGA
P2
C
O
N
N
EC
T
O
R
(26
PIN
)
PC-CARD-DAC08
DIGITAL
I/O
PORT
4 BITS
DIGITAL
I/O
PORT
4 BITS
ATTRIBUTE
MEMORY
DATA
BUS
OCTAL
D/A
CONVERTER
13-BIT
D/A OUT 7: 0
DIG I/O 3: 0
DIG I/O 7: 4
EXT INT
