HD1492 HD Encoder Frame Card
A
General-Purpose I/O
Each of the 2 GPIO input banks, Bank A and Bank B, has the following
pinout:
7
8
5
6
3
4
1
2
Bank A provides GPI inputs 1-4:
Input
Pins
4 (D)
7, 8
3 (C)
5, 6
2 (B)
3, 4
1 (A)
1, 2
Bank B provides GPI inputs 5-8:
Input
Pins
8 (H)
7, 8
7 (G)
5, 6
6 (F)
3, 4
5 (E)
1, 2
A GPI input is activated when closed (connected to ground), and inactive
when open (left floating). The even-numbered pin in a given GPI pair is
its ground. For example, GPI input 1 can be activated by connecting pins
1 and 2 of Bank A, thereby grounding pin 1. If pin 1 were left floating,
GPI input A would be inactive.
A GPI output’s pins form a switch that is on when closed and off when
open. For example, pins 3 and 4 of the GPI output bank form a switch
that is closed when GPI output 2 is active, and open when it is inactive.
35
