Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 171)

I/O Model Reference 161
Syntax
pin [output] frequency [invert] [clock ( const-expr )] io-object-name [= initial-
output-level ];
pin
Specifies either pin IO_0 (using the multiplexed timer/counter) or IO_1 (using
the dedicated timer/counter).
invert
This keyword inverts the output for an output value of 0. The default output
for 0 is low.
clock ( const-expr )
Specifies a clock in the range 0 to 7, where 0 represents the fastest clock and
7 represents the slowest clock. The default value is clock 0.
You can change resolution for the timer base clock frequency by calling the
io_set_clock( ) function with a clock value in the range 0..7 (using one of the
TCCLK_* macros defined in <echelon.h>). This function overrides the
resolution value specified for clock() within the I/O object declaration.
For an application running on a Series 5000 device, you can specify an
increased resolution for the timer base clock frequency by calling the
io_set_clock() function with a clock value in the range 0..15 (using one of the
TCCLK_* macros defined in <echelon.h>). This function overrides the
resolution value specified for clock() within the I/O object declaration.
See Appendix A,
Timer/Counter Periods and Resolution , on page 187, for a
description of the timer resolution and maximum range for each specification
of the clock() value or each value of the TCCLK_* macros. See the Neuron C
Reference Guide for information about the io_set_clock() function.
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 is limited
to 0 or 1. The default is 0.
Usage
unsigned long output-value ;
io_out( io-object-name , output-value );
Example
IO_1 output frequency clock(3) ioAlarm;
...