Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 177)

I/O Model Reference 167
Symbol Description Typical at 10 MHz
Note: The maximum value for t
jit
is 1 timer/counter clock period.
Programming Considerations
The oneshot I/O model can be retriggered. A call to the io_out( ) function for a
oneshot object starts a new pulse, even if one is currently in progress.
For oneshot output, the data type of the output value for the io_out( ) function is
an unsigned long. An output value of zero (0) forces the output to a low state.
Syntax
pin [output] oneshot [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
Causes the output to be inverted, producing a signal that is normally high
with low pulses. The default is normally low with high pulses.
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.