Hardware Reference
In-Depth Information
inputs or outputs, as required. This is carried out by simply writing appropriate
control words to the
control register
of each device.
Having configured the I/O port, it is then relatively easy matter to send data
to it or read data from it. Each port will appear as a unique address within the
PC I/O map and data can be read from or written to the port using appropriate
IN and OUT statements (or equivalent). Where the digital I/O lines within a
port group have individual functions, appropriate
bit masks
can be included
in the software so that only the state of the line in question is affected during
execution of an OUT command.
Characteristics of
analogue I/O ports
PC bus expansion cards for analogue I/O generally provide up to 16 analogue
input lines and several analogue output lines. Analogue I/O ports are often based
on one or more of the following devices:
Device
Resolution
Function
Package
Notes
AD573JN
10-bit
ADC
20-pin
AD557JN
8-bit
DAC
16-pin
AD574
12-bit
ADC
28-pin
AD667JN
12-bit
DAC
28-pin
AD1674JN
12-bit
ADC
28-pin
AD7226KN
8-bit
DAC
20-pin
4-channel
AD7528JN
8-bit
DAC
20-pin
2-channel
AD7528JN
8-bit
DAC
20-pin
2-channel
AD7542KN
12-bit
DAC
16-pin
AD7545KN
12-bit
DAC
20-pin
AD7547JN
12-bit
DAC
24-pin
2-channel
AD7569JN
8-bit
ADC/DAC
24-pin
I/O port
AD7579KN
12-bit
ADC
24-pin
AD7578KN
12-bit
aDC
24-pin
CMOS
AD7580JN
10-bit
ADC
24-pin
AD7681JN
8-bit
ADC
28-pin
8-channel
AD7672KN
12-bit
ADC
24-pin
high-speed
AD7824KN
8-bit
ADC
24-pin
4-channel
AD7846AD
16-bit
DAC
28-pin
AD7870JN
12-bit
ADC
24-pin
high-speed
AD7853N
12-bit
ADC
24-pin
high-speed
AD7893BN
12-bit
ADC
8-pin
serial interface
ADC0804LCN
8-bit
ADC
20-pin
ADC0809CCN
8-bit
ADC
28-pin
DAC0800LCN
8-bit
DAC
16-pin
TLC7524CN
8-bit
DAC
20-pin
ZN425E
8-bit
DAC
16-pin
ZN427E
8-bit
ADC
18-pin
ZN428E
8-bit
DAC
16-pin
ZN435E
8-bit
DAC
18-pin
ZN439E
8-bit
ADC
22-pin
ZN448E
8-bit
ADC
18-pin
ZN502E
10-bit
ADC
28-pin
