Echelon Neuron C - Manual (Page 115)

Neuron C Reference Guide 95
The io_in( ) call has an unsigned short return-value signifying the number of bits
actually transferred for a neurowire slave object. For other neurowire I/O object
types, the
return-value is void. See the Driving a Seven Segment Display with
the Neuron Chip engineering bulletin (part number 005-0014-01) for more
information.
parallel
For parallel I/O objects, the syntax is:
io_in (
parallel-io-obj , buf );
buf A pointer to the parallel_io_interface structure.
serial
For serial input objects, the syntax is:
io_in ( serial-input-obj , buf , count );
buf A (void *) pointer to a buffer.
count The number of bytes to be read (from 1 to 255).
spi
For spi I/O objects, the syntax is:
io_in ( spi-io-obj, buf, len );
buf A pointer to a buffer of data bytes for the bidirectional
data transfer.
len An unsigned short number of bytes to transfer.
The io_in() function has an unsigned short return-value that indicates the
number of bytes transferred on the previous transfer. Calling io_in() for a spi
object is the same as calling io_out(). In either case, the data in the buffer is
output and simultaneously replaced by new input data.
touch
For touch I/O objects, the syntax is:
io_in ( touch-io-obj , buf , count );
buf A (void *) pointer to a buffer.
count The number of bytes to be transferred.
wiegand
For wiegand input objects, the syntax is:
io_in (
wiegand-obj , buf , count );
buf An (unsigned *) pointer to a buffer.
count The number of bits to be read (from 1 to 255).