Touch input/output, Usage, Nibble input example – Echelon I/O Model Reference for Smart Transceivers and Neuron Chips User Manual
Page 53: Nibble output example
I/O Model Reference
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through IO_4. The lowest numbered I/O pin is defined as the least
significant bit of the nibble data.
io-object-name
A user-specified name for the I/O object, in the ANSI C format for variable
identifiers.
initial-output-level
A constant expression, in ANSI C format for initializers, used to set the state
of the output pin of the I/O object at initialization. The initial state can be
from 0 to 15. The default is 0.
Usage
unsigned int
input-value
;
unsigned int
output-value
;
input-value
= io_in(
io-object-name
);
io_out(
io-object-name
,
output-value
);
Nibble Input Example
IO_0 input nibble ioColumnRead;
unsigned column;
when (reset) {
io_change_init(ioColumnRead);
}
when (io_changes(ioColumnRead)) {
column = input_value;
}
Nibble Output Example
IO_4 output nibble ioRowWrite;
when (...) {
io_out(ioRowWrite, 0b1000U);
}
Touch Input/Output
The touch I/O model is used to interface to any peripheral device that implements
the 1-Wire
®
protocol developed by Dallas Semiconductor Corporation (now Maxim
Integrated Products). This protocol provides communications with Touch
Memory devices, iButton™ devices, and other similar devices. This protocol uses
a one-wire, open-drain, bidirectional connection.
The touch I/O model operates only within the timing specifications set forth by
Dallas Semiconductor Corporation for the 1-Wire protocol. This interface
supports bi-directional data transfers across a signal and ground wire pair. An
external pull-up is required, and the interface is connected directly to the