Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 26)

16 Introduction
• Driving a Seven Segment Display with the Neuron Chip engineering
bulletin (part no. 005-0014-01)
• Neuron Chip Quadrature Input Function Interface engineering bulletin
(part no. 005-0003-01)
• Parallel I/O Interface to the Neuron Chip engineering bulletin (part no.
005-0021-01)
• EIA-232C Serial Interfacing with the Neuron Chip engineering bulletin
(part no. 005-0008-01)
Declaring I/O Objects in Neuron C
Declaring an I/O object in a Neuron C application performs all of the following
tasks:
• Informs the compiler what type of I/O operation will be performed, and on
which pin or pins. The compiler creates instructions that configure the
hardware within the Neuron core as a result of this declaration. The
firmware configures the hardware whenever the device or application is
reset.
• Associates the name of the I/O object with an I/O model.
• Associates the I/O object with one or more I/O pins, and defines
additional properties of the I/O object.
The general syntax for declaring an I/O objects in the Neuron C language is
shown below.
pin direction model [options] io-object-name;
pin
One of the Neuron C keywords that name one of the twelve I/O pins, IO_0
through IO_11 (the IO11 pin is available only on Series 3100 power line
devices and Series 5000 devices). The named pin defines the first pin for
multi-pin I/O models. In general, pins can appear in a single object
declaration only. However, a pin can appear in multiple declarations of the
bit, nibble, and byte I/O object types. Also, IO_8 can appear in multiple
declarations of neurowire master specifying different select pins. In this
case, it is not required that all declarations have the same direction, that is,
input or output; see Overlaying I/O Objects on page 17.
direction
Specifies whether the object is an input or an output. Some I/O models are
bidirectional, and do not require the specification of direction.
model
Specifies the I/O model for this I/O object.
options
Optional I/O parameters, dependent on the chosen model for the I/O object.
The description of each model includes the model’s available options. Except
where noted, these options can be listed in any order. All options have
default values that are used when you do not include the option in the object
declaration.