Digilent DIO1 - Manual

D D i i g g i i l l e e n n t t D D I I O O 1 1
R R e e f f e e r r e e n n c c e e M M a a n n u u a a l l
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w w w . d i g i l e n t i n c . c o m
Revision: May 10, 2004 215 E Main Suite D | Pullman, WA 99163
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Overview
The Digital I/O board 1 (the DIO1) is one of
several expansion boards designed to mate with
Digilent system boards. The DIO1 is an
inexpensive board that contains an assortment
of basic digital I/O devices, including buttons,
switches, and several LED displays. The DIO1
board can be combined with Digilab system
boards to provide a source of ready-made I/O
devices, allowing a wide range of projects to be
implemented without the need for any other
components.
DIO1 board features include:
• A four digit seven-segment LED display;
• 8 individual LEDs;
• A 3-bit VGA port;
• 5 momentary pushbuttons;
• 8 slide switches;
• A PS2 mouse/keyboard port.
Functional description
The DIO1 board has been designed to provide a
basic, inexpensive platform that contains many
of the I/O devices commonly found in digital
systems. Unlike the more advanced DIO2
board, the DIO1 board has been designed so
that all signals pass directly to an attached
system board, so no intermediate logic is
required. When mated with a Digilab system
board, the DIO1 board can provide a flexible
prototyping system that can be operational
immediately.
LEDs
Eight LEDs are provided for circuit outputs.
The LED cathodes are tied to ground via 270-
ohm resistors, and the anodes are driven from
the 74HC373 (so the LED drive signals are
active high).
Figure 2. LED Circuit
Signals
All named signals used on the DIO1 board are
defined in the Table 1. Voltage levels for all
8 LEDs
4 displays 8 switches
PS2
port
Connector B
2
5
5 buttons
74HC373
Latch
Connector A
12
5
8
9
VG
A Po
rt
Figure 1. DIO1 schematic
LD signals
GND
LD1- LD8
RP1
270 Ohm