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Features and Operating Characteristics
P10-12 features and operating characteristics are described as follows:
• T h e PIO-12 has three TTL/CMOS-compatible, digital I/O ports: port
A, port B, and port C. Ports A and B are both byte-wide (8-bits) and
can be inputs or outputs. Port C is also byte-wide but is configurable
as two separate 4-bit ports (port C Lower and port C Upper), each of
which can be an input or output.
• T h e P10-12 has an interrupt input channel with a corresponding
interrupt-enable line. A PIO-12 interrupt can be directed to any of six
interrupt levels available on the PC bus.
• T h e P10-12 features its own enable line, which can be tri-stated
(interrupt enable - active low). The 8259 Interrupt Controller of the
computer handles interrupts and is set by the computer BIOS to
respond to positive-edge-triggered (low-high) inputs. You must
program the 8259 to respond to your application's requirements by
setting up the corresponding interrupt handlers.
• T h e P10-12 performs 10-bit I/O address decodes and communicates
with the PC Bus as an 8-bit peripheral. The address map uses four
consecutive I/0 addresses. Multiple P10-12 boards can be installed in
a computer at different base addresses.
• P o w e r levels of +5 V, -5 V, +12 V, and -12 V from the computer are
available through the main I/0 connector of the P10-12. If you plan to
use power from the PC, you should consider the power draw of all
system devices and observe current-capacity limits of the computer.
Accessories
The following accessories are available for use with P10-12 boards.
• S T A - U - screw terminal accessory. This accessory connects to the
main I/0 connector of the P10-12 through a C-1800 cable to make all
1/0 signals accessible through labeled screw terminals.
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Summary of Contents for PIO-12
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