Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 47)

I/O Model Reference 37
Table 14. Byte Output Latency Values for Series 3100 Devices
Symbol Description Typical at 10 MHz
t
fout
Function call to update 57 μs
t
ret
Return from function 5 μs
Programming Considerations
For byte input/output, the data type of the return value for io_in( ), and the data
type of the output value for io_out( ), is an unsigned short.
Syntax
IO_0 input byte io-object-name ;
IO_0 output byte io-object-name [= initial-output-level ];
IO_0
Specifies pin IO_0 as the least significant bit of the byte. Byte input/output
uses pins IO_0 through IO_7. The pin specification denotes the lowest
numbered pin of the set and must be IO_0.
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 255. 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 );
Byte Input Example
IO_0 input byte ioKeyboard;
unsigned int character;
...
when (reset) {
io_change_init(ioKeyboard);