Echelon Neuron C - Manual (Page 41)

Neuron C Programmer’s Guide 29
magtrack1
serial
wiegand
Serial Input/Output Model Types
i2c
neurowire
sci
spi
• Parallel I/O Models are used for high-speed bidirectional I/O. I/O models
within this group use all of the Neuron Chip or Smart Transceiver I/O
pins. The parallel I/O models include the following types:
Parallel Input/Output Model Types
muxbus
parallel
Declaring I/O Objects in Neuron C
Declaring an I/O object in a Neuron C application performs both of the following
tasks:
• Informs the compiler what type of I/O operation is 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 the hardware.
The general syntax for declaring an I/O objects in the Neuron C language is
shown below.
pin direction type [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 (pin IO_11 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 objects. 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 sense, that is, input or output;
see the I/O Model Reference .
direction
Specifies whether the pin is an input or an output. Some I/O objects are
bidirectional, and do not require the specification of direction.
type
Specifies the I/O object type.