Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 95)

I/O Model Reference 85
Programming Considerations
The data item unit is a single bit, and the maxbits and count values indicate the
number of bits that can be read, or have been read, respectively. In case of a
timeout, the count will be less than maxbits .
Syntax
IO_8 [input] magcard_bitstream [timeout ( pin-nbr )] [clockedge (+|-)]
[invert] io-object-name ;
IO_8
Specifies pin IO_8. The magcard bitstream input requires both pins IO_8
and IO_9. Pin IO_8 is the negative-going clock, IO_9 is the serial data input.
timeout( pin-nbr )
Optionally specifies the timeout signal pin, in the range of IO_0 to IO_7. The
Neuron Chip or Smart Transceiver checks the logic level at this pin whenever
it is waiting for either rising or falling edges of the clock. If a high logic level
is sensed on the timeout pin, the transfer is terminated.
clockedge (+|-)
Specifies the polarity of the clock input signal. The default is clockedge (-).
invert
Specifies that the data input signal is inverted. The default is no inversion.
io-object-name
A user-specified name for the I/O object, in the ANSI C format for variable
identifiers.
Usage
unsigned long count , maxbits ;
unsigned short input-buffer [ buffer-size ];
count = io_in( io-object-name , input-buffer , maxbits );
Example
IO_8 magcard_bitstream timeout(IO_7) ioMagcard;
const unsigned long maxbits = 64*8;
unsigned long count;
unsigned short input_buffer[64];
when (...) {
count = io_in(ioMagcard, input_buffer, maxbits);
}