Specifications

Chapter 12
PARALLEL I/O
Contents Page
OVERVIEW .................................................... 12-1
ZT 8832 SPECIFICS
............................................ 12-2
FUNCTIONAL DESCRIPTION
.................................. 12-3
Output Latch
................................................ 12-3
Output Buffer
............................................... 12-4
Input Buffer
................................................ 12-4
PROGRAMMABLE REGISTERS
................................ 12-5
OPERATION
................................................... 12-6
Reset
...................................................... 12-6
Programming the Parallel Ports
............................... 12-6
Programming the Light Emitting Diode
........................ 12-7
Mixing I/O in a Single Port
................................... 12-7
OVERVIEW
The three 8-bit parallel ports provide a total of 24 I/O signals. Each
I/O signal can be configured either as an input or as an output with
readback. The major features of the parallel I/O are listed below.
• Stable outputs during power-up and reset
• Data transfer rates up to 1 Mbyte/second
• Each I/O signal programmable for input or output with readback
• Direct connection to industry standard I/O module mounting
racks
12-1